1971 C-10 LS LM7 5.3 Carb swap on the cheap w parts list

[Pillow]

1971 C-10 LS Motor Swap

Drivetrain:
5.3 LS with Carb and LS2 camshaft
T-5 transmission from an S-10 truck.


Overview:
This motor swap was to be as economical and straight forward as possible for a simple truck. This is write-up will illustrate an LS that has been converted to carburetor, if you want to know about FI this probably isn’t the thread for you. Although the basic measures will be the same. Really getting to the heart of a basic truck that can run to the dump on weekends, commute for a daily if needed, and tow a travel trailer when required. This is not a hot rod or intended for track use in any way shape or form. In all honesty I should have kept the stock LM7 camshaft over the LS2 or at least settled for the LS1 camshaft since I will rarely see 6500 shifts. But don’t get me wrong, the LS2 cam has proved a beast even when lugging around town at low RPMs, no need to keep it wound up due to torque drop under the curve.

Resources:
All the information was obtained from the LS Parts and Interchange Swap book, WWW.LS1TECH.COM , and on WWW.67-72CHEVYTRUCKS.COM. Without the help of the great people on those sites, this project would never have been able to happen! So thank you all for contributing your knowledge! With all the help on the forums the books are really optional. The sources for the used parts were from Craigslist and Pick-A-Part, which are loved by all gearheads!

How To Rebuild GM LS-Series Engines
How to Rebuild GM LS-Series Engines (S-A Design):...
GM LS-Series Engines: The Complete Swap Manual
GM LS-Series Engines: The Complete Swap Manual...
http://ls1tech.com/

http://www.67-72chevytrucks.com/

http://washingtondc.craigslist.org/

http://www.pickapartva.com/


The Parts List:
This is a general list of the parts that I needed to get the transformation done. Where possible I will give the PNs and sources for the products used. Most items should be pretty straight forward and I tried to use off the shelf parts as much as I could to keep it simple.

• 5.3 LM7 pulled from a 2005 Chevy Avalanche which was a burn victim. All wires and intake on top were char-broiled to death. $300 and I pulled in owner’s driveway. Mobil1 oil religiously and it showed, a beautifully clean motor inside.
• Stock 350 manual bellhousing. Should be the same for I-6 motors as well. This covers the rear two mounting points to frame.
• Dirty Dingo slider mounts with stock new truck rubber mounts. I tried solid mounts first and nothing lined up right. Dirty Dingo is the way to go hands down and are priced right.
o http://www.dirtydingo.com/shop/index.php?cPath=359_360
• Non-World Class T-5 Manual Transmission from a mid-80s S-10 truck. Just be gentle! (future holds a built World Class T5 with S-10 T-5 case and Mustang internals)
o Follow the shenanigans: http://67-72chevytrucks.com/vboard/s...d.php?t=313954
• Flywheel is the, as recommended, replacement Sachs NFW1050 Clutch Flywheel. Good luck finding a stock one as so few manual LS trucks were built.
o Amazon.com: Sachs NFW1050 Clutch Flywheel:...• LS2 Pilot Bearing ACDelco CT1082 GM
o Amazon.com: ACDelco CT1082 GM Original Equipment...• Flywheel bolts new GM
• Pressure Plate can be reused with bored out 8mm holes converting it from Std to Metric. Needs purchase of PP mounting bolts. I used new GM.
• Z-bar for shift linkage was cut down to fit tighter space. In recent research, I think a stock I-6 Z bar would work in the conversion as they are shorter.
• A custom pivot will need to be made for the Z bar. No purchasable item exists. I used some flat bar from the local hardware store. $10 plus your fabrication time.
• Driveshaft is stock cutdown 2” and rebalanced by a local driveline shop. $100
• Headers are Hooker street rod shorties #2312.
o http://www.jegs.com/i/Hooker+Headers/520/2312/10002/-1
• ARP Header bolts
• Downpipe kit is RPC#707-R9795.
o http://www.jegs.com/i/RPC/707/R9795/10002/-1
• Exhaust is custom welded from a local shop in Manassas using Pro-Flo V-Force turbo mufflers. Turn outs are before axle and come out the sides.
o http://www.flopro.com/vforce.html
• Carburetor is a Street Demon 625 PN 1900. http://www.demoncarbs.com/1900.asp#1 Note that you will need the matching Demon air filter lid for clearance of the choke housing.
o Eventually I may try and go back to the stock Quadrajet, we will see.
• Air cleaner Demon 786004.
o Amazon.com: Demon 786004 14" Chrome Plated...• Air Cleaner Breather Port is Spectre 4960.
o Amazon.com: Spectre Performance 4960 Air Cleaner...• Edlebrock dual plane LS manifold 71178.
o http://www.jegs.com/i/Edelbrock/350/...oductId=755239
• MSD 6010 electronic ignition kit
o http://www.jegs.com/i/MSD+Ignition/121/6010/10002/-1
• LS2 camshaft sensor extension harness. Note that the Pink and Brown/White wires will need crossed.
• LS2 camshaft and matching beehive “yellow” springs. Used from LS1Tech FS area
• LS2 camshaft sensor assembly off Ebay
• Victor Reinz gasket kit, complete with head gaskets
• ARP head bolt kit
• ARP crankshaft pulley bolt
• JTR coolant breather kit. I cannot recall the sizes, maybe 1 5/8” to 1 ¾”. Measure and then order. I did not want to tap the stock water pump for a breather. Also this is the transition from C-10 upper coolant hose and the LS truck upper coolant hose. So this item is also a transition piece. I ordered sight glass with vent and 5/16” inlet for head steam vent breather. Powerful little item that I think is necessary to do right and is very nicely priced IMO.
o http://www.jagsthatrun.com/S-10_Order.html
• Prestone Green death coolant as I am not an air free sealed system.
• Upper radiator hose is stock truck 5.3 merged with stock C-10 upper using the JTR breather as an adapter.
• Lower radiator hose is Gates 21718, cut to fit. Half ends up in the trash.
o Amazon.com: Gates 21718 Lower Radiator Hose:...• Radiator is stock C-10 HD.
• Fan and fan clutch are stock early LS Chevy 2500HD truck “mechanical” unit from Pick-A-Part. No fancy electric fans needed!
• Heater hoses replaced with new, but stock C-10 units could be reused if yours are in good shape. Gates 5/8 and 3/4 are spot on.
o Amazon.com: Gates 28491 5/8 Inch Polybag Heater...o Amazon.com: Gates 28492 3/4 Inch Polybag Heater...• Fan Belt is a Dayco 5060680. Note that the only accessory is the alternator and one idler pulley has been removed. See pictures.
• Water Pump and Thermostat are stock.
• Alternator is stock truck 2500HD. Wired for I and S load off the fusebox with a resistor between I for proper input signal. Thread is here:
• Fuel pump is a Carter electric P4600HP. Quiet enough. Great mounting kit!!!
o http://www.summitracing.com/parts/crt-p4600hp/overview/
o Lots of good info and ideas in this thread: http://ls1tech.com/forums/carbureted...you-using.html
• Fuel tank completely stock.
• Fuel line is stock rubber 3/8” off the original C-10 tank.
• Fuel line pressure side is Earls SS braided hose -6 with AN fittings into the Demon carb. Totally optional and overkill.
• Fuel Filter is Wix 33003
o Amazon.com: Wix 33003 Complete In-Line Fuel...• Fuel will be Premium gasoline, just because I am paranoid of detonation with the lumpy LS2 camshaft. Lower grade fuels may work IDK. If retaining the stock LM7 camshaft, I think Regular grade fuel would be okay.
• Stock truck oil pan, just to be clear.
• Stock oil filters work, no changes here or remote mounts needed.
• Oil will be Mobil1 0W-40 or 5W-30 as recommended in the higher output GM performance vehicles.
• Oil Pressure Sender was converted from electric to mechanical to match the C-10 gauges. The stock unit can be “burned out” with a propane torch to remove the plastic sensor portion and leaves a nice aluminum shell that can be tapped on the top for 1/8NPT threads. Once tapped the stock C-10 oil pressure sender line be reused in essentially the same location on the LS engine.
o No thread that I know of, I just did it.
• Coolant Sender is an Autometer sensor and adapter. The stock C-10 coolant temperature dash gauge remains stock. The dash gauge reads on the lowest “normal range” indicator when the engine is fully warmed up. I guess that “red” would be in the middle. So far the temperature has not fluctuated at all on 90+ degree days.
o http://67-72chevytrucks.com/vboard/s...d.php?t=630830
o http://www.summitracing.com/parts/ATM-2277/
o http://www.summitracing.com/parts/ATM-2259/
• Future add will be the ‘76+ volt meter in place of the factory amp meter.
o http://67-72chevytrucks.com/vboard/s...d.php?t=630289


Tips:
• Buy a complete engine to start with. It makes your life so much easier in regards to hardware and not having to nickel and dime for small items later on.
• Have a good selection of electrical hardware and wire handy for connecting the electrical items. Trust me that parts adds more time and hassle than anything else listed in the conversion!
• Pay attention to the wiring for the camshaft if using a later model front trigger cam. See note above. Make sure and have the matching camshaft gear and cover for your application, sometimes not included in used FS exchanges.
• Pay attention to the wiring for the Alternator. Check output voltage. See note above.
• Don’t overspend! Use these notes and you can actually save more money than I did! For a truck, stick with a stock cam or LS1 which is an easy swap. If you get a solid motor that you know runs well, you can skip the gasket kits and ARP bolts which are expensive – but IMO if you need gaskets Victor Reinz is the best out there.
• These are high quality engines, the stock parts work! Don’t be afraid to buy junkyard items in a pinch, usually they will work.
• Buy a clean internal engine! If it looks like honey inside you know the owner took care of her with quality oil. If she is brown and dark inside then run. There are loads of these motors out there, be patient and find what you want. I would gladly pay more for a clean motor if necessary.
• Don’t get hooked on displacement or aluminum. The sub-6.0L bread and butter LS engines are plenty of power for most applications – with countless dyno sheets to prove it. The cost vs displacement advantage on the 6.0 and 6.2 are not worth it IMO. Stay away from the high compression Escalade motors, just not worth the hassle if going carburetor. And any of the AL blocks are priced too high to make them daily budget swap worthy, save those for the racers with deep pockets – plus the LS1/2/6s are generally more beaten on than grandmas Tahoe.

That is it in a nutshell! Please let me know if you have any questions!

Would I do it again? ABSOLUTELY! This engine purrs like a kitten at idle and sings like an angle when the revs fly. Hands down kills the old 350 in all aspects. Plus you can get real GM parts for the LS series motors where some of the Made in China trash replacement parts for 350s are a joke.

My only complaint is that now I have to go and uprate the suspension and brakes to keep the truck between the ditches!

[Pillow]

Clipped from MS Word... Formatting did not transfer a nicely as I would have liked.

Pictures and video will be posted this weekend. (didn't want to make it a teaser)

[Pillow]

Originally Posted by Pillow

Clipped from MS Word... Formatting did not transfer a nicely as I would have liked.

Pictures and video will be posted this weekend. (didn't want to make it a teaser)

Please ask away on anything I missed!!! It took a long time to gather and implement this information to make the install happen.

[nsulacountry]

Very complete write up on LS Carb conversion.

Pics will be nice when you get them uploaded.

CT

[solidaxel]

Great info!
Can I ask why you went with the carb over FI?

[Pillow]

IMO Carb just looks right under the hood of an old truck.

Honestly FI would have been cheaper as you really only need to worry about fuel delivery and the wiring harness to get up and running... Probably a tune as well once up. I am convinced the stock fuel tank, with external pump, can be reused if going FI as well which cuts the cost down considerably.

If going automatic with a 4L60E then FI is the logical choice.

The whole theme on mine was to try and stay as mechanical as possible. No frills, just go.

PICs are on my phone, just ran out of energy last night to upload them.

[Pillow]

Now some terrible phone camera pics! The sun glare was terrible. Sorry.

First the victim!


Clean engine shot


Hurst shifter for the T-5


Fuel pump setup on the passenger side rail


Burned out oil pressure sender to be tapped for 1/8 NPT


Installed to factory oil pressure line

[Pillow]

Z bar installed, but a bad angle to show how it lays in


JTR all in one coupler / sight line / breather


Fan belt setup and mechanical fan view, super easy and works!


Temp sender, hard to see detail


Relay off battery with 20A breaker to control MSD, Fuel Pump, and Choke.


Ants view of headers


Tucked mufflers


And side pipes

[nsulacountry]

Helluva job Pillow. You weren't kidding when you said basic mechanical. No AC, no PS. Hardcore roller!

How do you like the carb/MSD ignition setup? How does it compare to a 5.3L FI engine?

CT

[Pillow]

Heck I ADDED power brakes! I just couldn't leg the manual brakes anymore. Too stressful. LOL

Lugging around town, no big difference between the two. Even with the carb it starts first crank. The semi-annoyance I have is that when the carb secondaries open up the power rolls on almost too hard. Essentially an abrupt transition that FI would not have since it is smooth all the way through the pedal effort. Any 4 barrel person will have this issue I suppose. Honestly I have yet to really let the horses fly. Once I figure out how to keep her between the ditches, this will be ridiculous in a straight line.

Also the throttle cable is a little touchy on initial step in from a stop. But I think I can smooth that out. I had to roll the extra cable length which makes it harder to use than stock.

Probably nit picks, but other than that she has been great.

I will probably end up doing a couple more LS conversions on other vehicles down the road. It is a great engine and the $ per HP is just straight cheap!

[Pillow]

Crap, I just chomped #7 rod bearing this weekend. Odd as it had been running wonderfully for about 400 miles.

Serves me right for not replacing the bottom end bearings while doing the heads on the engine stand. Dang!

[nsulacountry]

ouch. just rod bearing? or did it cause crank problems too?

CT

[Pillow]

Not sure yet... Hopefully I'll be able to pull the oil pan this week and look from the bottom. Ugh what a depressing life event! lol

[Pillow]

FML, took out the 5.3 last weekend and tore it apart. Insides looked perfect!!! I suspect I actually had a weird ground problem on the 6010. More to come with photos. But according to MSD, both heads need grounded to the 6010 then to body ground and battery ground. I just had the MSD grounded to block and body/battery with 0 gauge.

One problem... The Edelbrock intake bolts are WAY too SHORT! pulled threads in multiple head female side holes. I purchased longer bolts, I hope they fit with more thread bite/length. The Edelbrock bolts aren't even a true 50mm. Sad. I'll post pics and a PSA to the board when I have a solution.

The good news is that the motor internals looked great! But since it is apart, new mains, rods, and rings will be put in. Why not!

Placing the LM7 cam back in. The LS2 is just too brutal for what I need. (it will go back in the box for another project)

Just let me know if anyone has picture requests!

[Pillow]

Update!

Engine is refreshed and back in the C10. Went for a short drive and have a miss up in the revs and at idle, sporadic. Not carb or mechanical. So I still need to dig in to figure that out.

4 gauge ground from head to head has been installed.

I'm going to move the main ground to chassis and see if that helps.

Other than that, maybe one of the sensors (crank/cam position) is a bit off.

Interestingly enough, the oil pressure reads higher with the new bearings versus the old good "used" original bearings.

Soon it will be out terrorizing stock Civics! LOL

[Pillow]

Switched ground locations to frame rail. Now I have 0.000 Ohms resistance from head to head to frame rail passing through the battery negative. So that is great!

Still a little miss...

I'm going to go a heat range higher on the plugs and see if that helps. IRRC they are NGK TR55 now. Moving to TR6, but will verify later.

Thanks!

[Pillow]

Ordered a CKP (Crankshaft Position Sensor) seems like the classic symptoms.

I'll let you all know if that does the trick.

More pics and a video tonight to post!

[nsulacountry]

CPS will do it! Keep us posted.

CT

[Pillow]

More pics and updates!

* So far I cannot comment on the CKP yet. Need more seat time.

MAP Sensor installed. So easy with the Edelbrock side port. Just a small piece of hose and done. IDK why I didn't do this sooner!





4 gauge ground from head to head


PSA!!! The intake bolts that the Edelbrock intake come with are TOO SHORT! Look at the one on the left and how it stripped after heat expansion. The replacement on the right is 60mm. Run a tap through your intake bolt holes when the heads are off (otherwise your combustion chambers will eat the shavings). This IMO is a huge failure on Edelbrocks part, thier bolts aren't even a true 50mm!



On Beer break! Chair and beer fridge not pictured

[Pillow]

Update! After fighting the damn stock MSD harness on a passenger side miss ( all 4 coils) I ended up buying the MSD 60101 harness for carb applications. Awesome fit and has extra length for the crankshaft sensor!

If you are going carb, I highly recommend this harness.

Now time to rack up some miles!!!

[americanmusc1e]

Nice Swap!!

I have a couple of questions..

What clutch did you use with that Sachs NFW1050? I'm doing a SM465 to 5.3 and I'm using that same flywheel/pilot bearing.

How much low end did you loose with that LS2 cam. My Sm465 drops a lot of RPM between shifts do you think it would work?

[MalibuSSwagon]

Originally Posted by americanmusc1e

Nice Swap!!

I have a couple of questions..

What clutch did you use with that Sachs NFW1050? I'm doing a SM465 to 5.3 and I'm using that same flywheel/pilot bearing.

How much low end did you loose with that LS2 cam. My Sm465 drops a lot of RPM between shifts do you think it would work?

I used Exedy 04081 clutch kit with my 5.3L/SM465 swap. Stock clutch application for my truck. Works great for Daily driving and towing 6k+ is not an issue. I'm on the stock LM7 cam and stock tune as well.

[Pillow]

Hey Josh, the clutch is the 4.3 manual Astro Van. I do not recall PN, but there is only one part and many of the T5 converters use it. The disc could be bigger, but no slipping so far. On the higher end, there is a Centerforce upgrade, but that is spendy if you do not need it.

So far the LS2 cam has been a dream! I have been DD the truck for two weeks as the Saab is barfing oil from a mystery location.

Honestly there is SO much power that the stock truck LM7 cam would be fine as well. People don't really comprehend how much power is in these LS motors. In my case, if I wanna shift at 6500 it better be in 1st/2nd or the truck is going faster than I wanna go in a truck! 99% of the time she is just purring down the interstate passing Prius's hogging the left lane.

Normal open highway she is very content between 1500-2000 as a cruise. at 2000 I'm passing a lot of cars, so I estimate that is about 70-75 and is all that I wanna do.

As for the drop between shifts for your SM465, remember that the LS loves to rev (with the right cam). I do not see any problem shifting at 3500-4000ish and still not stressing the motor at all (a mear valvespring upgrade gets u safely to about 7000). This is a different animal than a typical 350 or inliner.

If I can get the clutch PN today I'll post it up.

[Pillow]

Updates!

This setup has been a dream and running like a champ for years. She has gone to Dallas TX and back twice loaded.

... But time to tinker some more. Last week I took the Carb stuff off and headed to FI. Specifically FiTech 70050 system.

Why? To gain a little bit more economy and to make ready for winter. I figure FI will be a snap in the cold.

Still this C10 is a hoot at 6500 RPM!!!

Adding: I'll post up the complete parts list as well. El cheapo fashion as always! No chrome, No BS, and as stock GM as it can be.

Note: If you don't change cams, the stock ECU service from LT1SWAP.COM would be the way to go. Cheap and easy. But with the LS2 cam I cannot do that, so I opted for the FiTech system. Cheaper to get an adaptive system than "tuned"/programmed.

[Captainfab]

Interested to hear your input on the FI upgrade.