Scott's '51 Build - LSx questions

[Scott2]

I have a 1951 Chevy 3100 that I bought recently and have just started working on. I have an TCI IFS/4 link rear, coil-over chassis on order, set up with LSx and auto trans mounts. I want to use either 18 or 20" wheels, and will run it lowered.

So now that I'm looking for a motor and trans, I have read thru a ton of posts here and elsewhere. I may be on info overload and no doubt missed a few bits of info.

Out of all the reading and options I decided I would go look for an LQ9/4l60/80e combo (aka VortecMax) out of a truck or Escalade. This seemed to make sense to me and is a great combo but then I realized I'm not sure if the truck pulleys, etc. on the front of the motor will clear the radiator, or the truck oil pan will give me enough ground clearance.

I have read about some of these issues but they didn't seem to be in this generation truck. I also see some builders were swapping to car accessory drives and pans? So if I am starting out looking for parts - do I look for truck motor/trans plus car parts, or look for car motor/trans? If so, do I need other parts or truck parts or?

I may have missed a post that answers this and if so I apologize, just please point me in the right direction. Otherwise, I would love some advice on this subject to try and get my head straight.

Thanks!
Scott

[clinebarger]

I have built a couple AD trucks with truck 5.3L's, Both with set-back firewalls http://www.absolutesheetmetal.com/co...evy-pick-parts

The oil pan will need to be changed on a lowered truck, '98-'02 Camaro/Trans Am pans fit great with the engine set-back.

The Truck front accessories fit good with a Fatman (Mustang II) front suspension, The power steering fittings at the rack are close to the PS pump.

Of coarse I can't tell you they will work with a TCI set-up

[e015475]

This is a 5.3 truck engine from a Trailblazer in a 49 GMC (at mock-up stage). The motor sits into the firewall about 2". With a truck crank pulley as shown, the distance to the front of the radiator support is 8.5". With the Corvette intake, the distance to the plastic flange for the throttle body from the radiator support is 13.25" (will have to either modify the truck water pump neck or use the late model Camaro pump to use this intake)



If you use the F-body accessories on the truck, you'll get about another 3/4" and the Vette, about 1 1/2". You may have some problem clearing the driver's side inner fender well with the Vette alternator if you go this route

If you have the room to the front cross-member, the F-body pan works well. On this truck, I jacked the engine up just a bit so the bottom of the truck pan I used was nearly level with the front cross-member.

Since I want to use factory pedals and a manual trans, I'm planning on making the headers. If it wasn't for the manual trans/pedals, a set of shorties for the late model Camaro looked like they'd have worked.

[Scott2]

Thanks guys! So - Camaro pan and truck accessories. I had not considered the firewall.... I will have to look into that further.

Thanks!
Scott

[Scott2]

clinebarger,

Thanks also for the link. Which firewall did you use - the 751000 or the revised version? What effect does this have on the interior?

I really like the entire floor sheetmetal set concept which all mates to the setback firewall! I'm not yet sure how much I need but it looks like a great option if the floors are all bad.

Scott

[solidaxel]

We are using a Tahoe 2003 5.3 Scotts IFS in a 46 1/2 ton with truck acc drive and a different A/C bracket stock pulleys and balancer with a electric fan and there is just enough room for everything.
Did not have to cut the firewall or move the radiator core support from the stock location

[aknovaman]

Is the 46 engine bay shorter from radiator to firewall than a 51 ?

[Scott2]

solidaxel -

Thanks! The pictures are great.

Scott

[Scott2]

moved the reply

[solidaxel]

Originally Posted by aknovaman

Is the 46 engine bay shorter from radiator to firewall than a 51 ?

It sure seems like it to me, I have never measured them, but I spend a lot of time looking into both of them

[Scott2]

Today I found an 80k miles LQ4 from a 2006 Chevy Silverado 2500. Engine only (no trans) plus all the wiring and computer, gas pedal, and airbox. The yard wants $1800 for it which seems pretty reasonable. Is it?

This truck should have come with the 4L80e transmission, but it's already gone. What will I run into in matching up another tranny? Are there years to look for or avoid to make it work right with the engine?

How about tranny wiring and controller?

I'm not even sure what to ask so any guidance would be greatly appreciated!!

If I know what to look for I might just buy a rebuilt trans - any recommendations for suppliers?

Thanks!

Scott

[aknovaman]

Thats a fair price. Search craigslist for diesel trans. I got an 80e for $275 from a diesel. Just swapped in a gas motor torque converter and i was good to go.

[clinebarger]

Originally Posted by Scott2

clinebarger,

Thanks also for the link. Which firewall did you use - the 751000 or the revised version? What effect does this have on the interior?

I really like the entire floor sheetmetal set concept which all mates to the setback firewall! I'm not yet sure how much I need but it looks like a great option if the floors are all bad.

Scott

Used the original 751000, Ran a Hydroboost & Master under the floor.

[Scott2]

Originally Posted by aknovaman

Thats a fair price. Search craigslist for diesel trans. I got an 80e for $275 from a diesel. Just swapped in a gas motor torque converter and i was good to go.

What did you do to connect the trans controller to the engine wiring harness?

Scott

[clinebarger]

Originally Posted by Scott2

What did you do to connect the trans controller to the engine wiring harness?

Scott

Transmission function are built into the PCM on a '06 2500HD, If you already have the PCM & Harness....All you need is a 4L80E. If you want to run a 4L60E you will need a Trans segment swap performed on the PCM & wiring harness modifications.

'04-'08 are the best 4L80E cores, Though '97-'03 are good to. The '94-'96 are OK. '91-'93.....Most are worn out!

Stay away from 4L80E's from Duramax Express vans unless its for Core price ($250), The 4L80E is a stout unit, But don't hold up to the torque rise of a Duramax.

[Scott2]

Great info all around - thank you guys! This forum is an awesome resource!

I am closing in on buying the 2006 LQ4 6.0 motor (Chevy Silverado 2500 donor) and they are looking for a suitable 4L80e trans and Camaro pan.

Scott

[solidaxel]

Have you thought about the Hydro-Vac on that 2500 for your power brakes?

[Scott2]

Originally Posted by solidaxel

Have you thought about the Hydro-Vac on that 2500 for your power brakes?

Honestly - no. Generally I don't know anything about that system, but specifically, my TCI chassis comes with a below-floor vacuum brake setup. What's the advantage?

Scott

[aknovaman]

4x the breaking force.

[e015475]

Believe GM calls them 'hydroboost'. All Astrovans have them and the you-pull-it junkyards are full of them for $20-30 each. As previously said, the advantage is low pedal effort. The Astrovans have a reservoir that they say is good for a couple of stops even if the engine is dead. Google 'hydroboost' and you'll see lots of conversions.

[solidaxel]

.............. I'm up for a $30 dollar one!!

[e015475]

There's two varieties from the Astrovan - an early one and a late one. The late ones have a 15 degree tilt to them and are harder to make look nice, while the earlier ones are straight. The division is about 1996. See quite a few of the vans on CL here and I might check them out. The self-serve junk yards open early in the summer in Phoenix, but it is hell-hot here now - 113 today - so will start looking in October. Hope it is cooler for you in the Cactus Patch.

[Scott2]

Originally Posted by clinebarger

Transmission function are built into the PCM on a '06 2500HD, If you already have the PCM & Harness....All you need is a 4L80E. If you want to run a 4L60E you will need a Trans segment swap performed on the PCM & wiring harness modifications.

'04-'08 are the best 4L80E cores, Though '97-'03 are good to. The '94-'96 are OK. '91-'93.....Most are worn out!

Stay away from 4L80E's from Duramax Express vans unless its for Core price ($250), The 4L80E is a stout unit, But don't hold up to the torque rise of a Duramax.

I posted another thread asking about the trans cores and just realized you had already given me the answer! Too many questions swirling thru I guess.

I have found a good looking (no leaks, no damage, fluid is the right color and smells fine, converter doesn't have any overheat signs, not sure what else I can tell with it sitting on a shelf...) ~1999 2WD 4L80e with 156k on it for $700 which I think I will buy.

Anything else I should look for or do to determine if it's good?

Thanks!
Scott

[Scott2]

I also had a question about the wiring harness. I got a full wiring harness and PCM plus DBW pedal assy, etc. with my 6.0 LQ4. I was also offered a brand new stand alone harness set up for an earlier year LS (cable operated gas pedal and throttle body). The guy wants $500 for the harness and will trade out a cable gas pedal and throttle body. After doing a bit of searching and talking with the tech at Painless, I think this could be a good way to go. Thoughts?

I should be able to sell the original harness.

Scott

[clinebarger]

Originally Posted by Scott2

I posted another thread asking about the trans cores and just realized you had already given me the answer! Too many questions swirling thru I guess.

I have found a good looking (no leaks, no damage, fluid is the right color and smells fine, converter doesn't have any overheat signs, not sure what else I can tell with it sitting on a shelf...) ~1999 2WD 4L80e with 156k on it for $700 which I think I will buy.

Anything else I should look for or do to determine if it's good?

Thanks!
Scott

That's a million dollar question....You don't know for sure without tearing it down, If you decide to tear it down, I can walk you through it, They are easier than a 4L60E for a novice to build, Let me know.

For the harness & computer, It doesn't really matter, DBW vs DBC is a preference more than anything.

Your 2006 intake will not have the inserts to bolt down the throttle cable bracket, The O2 sensors off the '06 will probably not work on a earlier harness (connectors)

Is the new harness & computer set-up for a 4L80E?