LS Swap: Introduction, newbie, planning...

[ls1nova71]

Does the engine have 706 heads? If so, could be a set of Castech heads that were known for cracking.

Also, the '98 coolant temp sensor may move the gauge in a '72, but won't be accurate. Tried that 20 years ago on my '71 Nova, which I'm sure uses the same internal gauge parts and it didn't work.

[clay68c10]

You will need to experiment with the gauge resistor to get that sender/gauge combination to work correctly. That said, I will be doing the same. Just know that it’s not plug and play.

[Davidf]

Originally Posted by ls1nova71

Does the engine have 706 heads? If so, could be a set of Castech heads that were known for cracking.

Also, the '98 coolant temp sensor may move the gauge in a '72, but won't be accurate. Tried that 20 years ago on my '71 Nova, which I'm sure uses the same internal gauge parts and it didn't work.

No, 862 heads. Could not find the Castech foundry mark. Part of me is starting to wonder if I have a head gasket leak. I think I will pull the heads, inspect and then take the heads to the machine shop as I will want them freshened up regardless. The shop can pressure check them for me.

[Davidf]

Update:

Machine shop said 862 heads passed pressure test, so I had the heads resurfaced and valve stem seals replaced. We both now suspect a leaking head gasket.

Over the weekend, I got the LM7 reassembled with new lifters, timing chain, and of course seals. I went ahead and painted the block Chevy Orange. I used an EngineTech gasket set and found that I did not trust the oil pump pick-up tube o-ring, so I purchased a replacement from a Chevy dealer. Also, the kit did not come with the oil galley expansion plug so that was sourced from the dealer as well.

I started on the engine wiring harness mods and received my computer back from LT1SWAP. The wiring is bit more complicated as I am keeping the a/c going through the computer (for idle compensation when compressor is activated) and the pressure safety switches.

Next up will be cleaning the transmission to get it ready to reattach to the engine just before I am actually ready to make the swap. My C10 is on the road currently, so I want to make sure I have most of what I need and all parts modified before I actually attempt the swap.

[Davidf]

Update:

Engine is done and fully assembled on the stand. Been working on the wiring harness and have the fuse/relay box 100% wired (included relays for A/C and Condenser fans. Spare relay socket for future radiator fans, if I go that route).

Now, reason for my post: What fuse size/amperage should be used for all the fused circuits? I followed lt1swap website for grouping systems on fuses. For instance:

Fuse 1: Coils and ECM/PCM keyed power (relay 1 controlled)
Fuse 2: Fuel injectors (relay 1 controlled)
Fuse 3: Transmission, MAF, (heated) primary oxygen sensors (relay 1 controlled)
Fuse 4: Fuel pump (relay 2 controlled) and ECM/PCM constant power
Fuse 5: A/C compressor (relay 3 controlled)
Fuse 6: Dual condenser fans (relay 4 controlled)

[Davidf]

An update for anyone that cares...

Over the weekend, my son and I got the '01 5.3L LS mounted in the '71 C10. As noted above, I went with the Hooker engine stands, F-body mounts, and Hooker transmission cross member. Let me tell you, the engine is a tight fit even in the seemingly large engine bay. I had to clearance the left frame rail to clear the power steering pump return line. Just past the pump (toward the rear) the frame narrows, so I just made the frame look like it narrows further forward than factory. If you did not know otherwise, you would never know I cut on the frame...nice clean line. I used the '01 Tahoe LS trans cooler lines and they will need a bit of rebending as they hit the front frame cross member. And, they are rubbing on the main cross member (tight fit here). But, I think I can make them work.

Now, as for the Hooker Blackheart engine mounting solution, I like it. But, the engine stands need a bit of quality control work as on one side, the ears on the stand was 1/8" too narrow. That meant grinding 1/8" off the mount bolt tube. The trans mount is a nice piece of hardware. The Hooker solution keeps the engine very low in the engine bay. As such, there is plenty of clearance for the a/c compressor, but necessitated the clearancing for the PS pump. Supposedly driveline angles are maintained. I also kept the truck oil pan and it clears the drag link by about 1/4"...works for me. Wire harness follows factory routing in front of oil pan, I got rid of the plastic factory bracket and camped the wires to the front oil pan bolts...perfect.

Only collateral damage was breaking the retaining tabs off the MAP sensor...dang, should have left it installed. I guess some cleaver zip tying will fix that problem. Probably only needs to be retained in case you get a intake backfire...otherwise, not sure how it would come out anyway.

The Trailblazer SS manifolds clear the frame fine without the need to do any frame clearancing.

Also, got new '87 C10 a/c evaporator mounted in air box (prior to installing engine). And, firewall has a fresh coat of paint...sorry it is all covered, but been raining in Central Texas a lot lately.

Now I get to start on the fun part...all the connections.

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[ls1nova71]

If you're running the factory Vortec engine cover, then the rear mounting bracket will hold the MAP sensor in.

[Davidf]

Originally Posted by ls1nova71

If you're running the factory Vortec engine cover, then the rear mounting bracket will hold the MAP sensor in.

Oh, good to know. Yes, I will be using the Vortec cover. Sweet.

[1957 Chief]

Originally Posted by Davidf

[IMG][/IMG]

Looks great man!

[gmc684x4]

If you use 98 camaro temp sender late square body truck temp gauge should be able to swap in the cluster and match the 98 z28 sensor

[gmc684x4]

I see you have the engine in the back position can you show how tight is that to the fire wall does that make a tighter then a sbc in that position ?

I am using a 96 suburban tank cutting the pump retainer out of a 99 express van and use the 03 truck pump assembly with a tanks inc sender correction box is $ 90 at summit

[Davidf]

Plenty of clearance at firewall and easy access. I took some photos, but will have to wait until back at office to post.

Made some progress yesterday:
Salvaged fuel lines out of donor, straightened and rebent to follow left frame rail and up firewall so factory rubber hoses connect to fuel rail. Used throttle pedal bolts coming through firewall as anchor points. Used factory fuel filter and bracket to mount on frame rail. In tank fuel pump and connection to fuel filter remains. Return line parallels supply.

Salvage exhaust down pipes out of donor, right side factory 90 is in perfect spot. Left side will welded up so it turns inward slightly and then rolls back to rear right below trans linkage.

Relocated trans linkage bracket, narrowed linkage and connected all to trans.

Cut end off donor throttle cable and shortened as much as possible so enough inner cable in cab to connect to pedal. But it is too short now. Anyone know of a longer cable than came in 01 Tahoe? Need to redo this part.

Pulled out all the windshield washer hoses...wiring harness will enter cab where washer hoses were. Anyone know best remote electric washer pump?

[gmc684x4]

I have 3 washer jugs going to see what fits the best new 00 corolla washer jug and pump washer jug and pump from 92 c1500 and a jug from a 03 k1500
I plan on stock air filter i scrounged up factory auxiliary battery plate assembly

I haven't pulled my motor yet working on peicing together my chassis first plan on reusing what I can tranny donor van has plastic fuel lines not sure yet about the truck
Summit has a good fuel line crimper to make factory style crimps

[Davidf]

Originally Posted by gmc684x4

I see you have the engine in the back position can you show how tight is that to the fire wall does that make a tighter then a sbc in that position ?

I am using a 96 suburban tank cutting the pump retainer out of a 99 express van and use the 03 truck pump assembly with a tanks inc sender correction box is $ 90 at summit

Plenty of clearance. +/- 1.5" from left cylinder head to closest spot on firewall...
Transmission (4L60e) is about 1/4" from touching low hump tunnel.
Next up...front clip goes back on. Have my three sons coming home to help tomorrow night...

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Better overall photos:
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Modified the battery tray to move from right to left side...
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[Rich84]

Try a cable off of an S10. It fit well on mine.

[Davidf]

Any particular year of S10? I want the factory cable look, so Lokar is out. I have heard a bicycle brake cable will work, might try that.

As for an update on my project, with the help of my three sons, we got the front clip reinstalled and adjusted. A bit of collatteral damage as the inner fender snagged the front brake line coming off the distribution block and broke the pipe. And, some chipped paint under the cowl (no one will see it, but I know it there). Surprised how small that front brake line is 3/16". But, it will be an easy task to bend up and flare a new line.

Also, one of the transmission cooler pipes got pinched under the inner fender. We kinked it trying to get it out from under the liner. Not a big deal as the radiator side of the Tahoe lines had a lot of bends that wont work. Instead of re-bending the 3/8" lines, I cut them just in front of the engine and will use new 3/8" lines bent how I like them and connect to the radiator with an adapter fitting (BLF-18) that reduces the 3/8" line (5/8" inverted flare nut) to 1/2" inverted flare

[ls1nova71]

If you have a pick n pull close, you can get a throttle cable off of a van as they are about the longest cables you will find, then cut it and the original one apart and combine the two. Astro vans are plentiful around here and work well. I have pics in my build thread, post #34. https://ls1tech.com/forums/conversio...-c-10-a-2.html

[Davidf]

Originally Posted by ls1nova71

If you have a pick n pull close, you can get a throttle cable off of a van as they are about the longest cables you will find, then cut it and the original one apart and combine the two. Astro vans are plentiful around here and work well. I have pics in my build thread, post #34. https://ls1tech.com/forums/conversio...-c-10-a-2.html

Yes sir, I followed you post on modify the Tahoe cable. But, it is just too short (and I have my engine set back). I'll find one somewhere.

[Davidf]

Update: Making progress. Radiator in, trans cooler lines complete, air box mounted, battery tray relocated. Computer mounted behind front left fender, cruise control servo mounted. Engine wiring bundled and routed. Truck engine compartment wire harness thinned and reversed (due to battery relocate). LS mechanical fan and '71 fan shroud are playing perfectly together.

Left to do: Fuel system, exhaust, wiring inside cab (you can see cab wiring pigtail in photo...it will go through hole for windshield washers, electric condenser fan wiring, body power wiring, a/c, heater hoses, cruise control lever/wiring, single piece driveshaft, trans fluid/filter change.

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[kev2809]

great progress....hope to get on mine soon!

[Davidf]

Update (Sorry no photos):

I made the 2001 Tahoe throttle cable work, but it is tight from engine to firewall and barely enough inner wire to put the cable stop on. Opens to WOT.

ALL engine compartment wiring is complete, including fans on condenser, grounds, headlight relay kit, etc. Only questionable wiring is the ammeter...we'll see if it works later.

Working on getting the a/c plumbing done...not easy. Had to pull front grill and will have an a/c shop make a hardline with proper ends that eliminate the drier and go through the same hole in the core support. Will order two sets of compressor adapters - one set that goes straight up, for the low side. And, one set that goes straight forward (already have on hand), for the high side (cannot use straight up because of frame interference).

Cruise control switch lever relay pack wiring is complete. Relays convert normally closed cruise switch to normally open. Using the Rostra lever/switch.

What's left to do:

Complete a/c plumbing and charge.
Under dash wiring: OBD2, cruise control, check engine light, TCC, etc.
Fuel system: in tank pump, hard lines (1/2 done)
Exhaust system: will go with Thrush kit.

Getting close.

[Davidf]

Update:

In tank fuel pump is fabricated and mounted in tank. All fuel lines run...fuel system complete.
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All under hood wiring is complete and a/c lines fabricated and connected.

Left to complete: exhaust, complete in-cab wiring, install volt meter gauge, speedometer drive.

[Davidf]

Update:

Completed (mostly) the build this weekend and started the engine for the first time Saturday, 7/17/21. Fired right up on first turn of the key.

Left to do:
1. Exhaust system. Probably going to sub this task out.
2. Rebuild rear axle and add limited slip.
3. Monitor rear main seal for oil leak (may have botched the seal install). It was hard to install with the engine on the stand.

[Davidf]

New update:

Decided to have the exhaust shop tackle the leaking rear main seal. Turns out the crank has radial movement and the new seal still leaks, but not as bad. But, the new exhaust sounds pretty good, maybe a little on the quiet side (Flowmaster 50 series). Only thing they did wrong was choke (dent) left side pipe due to shifter linkage interference...

So, engine runs good but looses oil pressure when hot. My assumption is worn out crank bearings (probably cause of radial crank movement...you can see flywheel move when spinning).

Another problems is that my cruise control does not work. Used normally open controller with polarity reversing relays. When I push the set button, I can hear the relay...but nothing happens.

So, started my search for a replacement used engine. Don't feel like rebuilding what I have. So, how do you ensure you get a good used engine...pure luck? Thinking of taking my bore scope to salvage yards and peaking under the valve cover...if clean then winner winner chicken dinner.

[notsolo]

It Maybe, pure luck, I spent a good bit of time looking, I just got mine running yesterday. Seller posted video and vin number on a 2001....with the vin you can see a little bit of the history. How long it was owned etc. Best of luck with the search.