Hi guys, I am just starting a new project. I have a 52 Chevy Panel truck that I am doing a full frame off build on. I found a 2002 8.1 out of a 3/4 ton Chevy 4X4. The truck was wrecked in transit to the dealership so the engine has 2 miles on it. I can pick up the egine, tranny, transfer case, ecm and wiring harness for $5000. I have done engine swaps before but never with so much electrical involved. Here are my questions-

1) To get rid of the transfer case and convert to 2 wheel drive do I just need a new tail section on the trans or is it easier to get a two wheel drive trans? How will this affect the electrical part of the system? What about the new 6 speed auto that Chevy has?

2)How do I integrate the electronics with a new system- such as the gas pedal drive by wire system, etc? Is there a company that makes a "miracle" harness to make my life much simpler?

3)Are there any aftermarket manufacturers for appearance parts such as pulley kits, valve covers, etc.


If I can get this figured out the truck will get the new cam/heads 8.1 with a Radix supercharger to move it down the road. If not I will build the 502 NA that I originally planned.
Thanks for the guidance!!!

 

For wiring, I called Speartech.

Click the link over there ----->

 

what transmission is it? allison? and what size is the throttle body? the 8.1 is a whole different animal from what most of us here are used to dealin with, as it is outside of the gen 3/4 smallblock family.

 

i thik its the newest gen bigblock. im not 100% sure but basically gm just developed the injection setup for.

 

The trans should be a 4l80E to convert to 2x4 you will need to swap the out put shaft to the longer 2x4 version, you will have to completely take it apart to swap them! And get a tail shaft with a VSS in it to shift the trans and run a eletric speedo. The six speed aren't even out yet. And would be expensive!

The thottle should not be thottle by wire on a 2002 just run a cable to a lokar pedal. Painless makes harness but I would use the stock one if you have it and run custom gauges and adapt them to the engine.


Contact Street and Performance they have the 8.1 stuff and do custom stuff as well.


I would make sure and beef the frame up or go with a custom frame. Aren't those trucks open c frames I would at least box the frame or you could wind up in trouble!

 

I realize that the engine is from a different "family" than the ls1. You guys just really seem to know your stuff and they are similar.

Bo185- The frame will be built to handle. I am retaining some of the stock frame- boxing it, tubular crossmembers, c notch, fatman front clip. Basically the frame rails from the firewall to the rear axle hump will be stock/modded and the rest will be custom fabbed.

Thanks for the advice- keep it coming.

 

The 8.1 is the big brother of the family and is the new big block!

 

Does the 8.1 have all of the advanced tech that the LS1 has, like 6 bolt mains and and awesome intake like the LS1?

 

The 8.1 is baised off the big bock family, gen VI to be exact. Its similar in the fashion that it uses the same electronics and ecm than the ls1 uses. Tuning wise it'll be similar to tuning a LSx based chevy truck.

Sounds like it'll be a great project. I attempted to get a friend to do a similar swap in a 58 chevy 3500. Would of been rather rare!

 

Well I can offer I little help here. Besides an LS1 Firehawk I also have a 2001 Silverado HD 4x4 with the 8.1 and Allison transmission. I'll try to clear up a few things first. The only 8.1's that have the 4l80e come in the Avalanche and Caddilac SUVs. All GMC and Chevy truck 8.1's have either the ZF 6spd manual or the Allison 5 speed auto. The stick shift throttle is cable actuated all autos are drive by wire. The electronics and wiring for this particular drivetrain are very complex. Torque managment sucks. The Allison has it's own computer and the ECM and PCM work together to get the job done. One won't work without the other. Your best bet would be to try using a ZF 6 speed computer, wiring, and throttle body with a traditional GM trans such as a TH400, 700R4, or 4L80E with stand alone PCM. This would give you a more do able and workable drivetrain. The Allison is a wonderful workhorse, I wouldn't dream of having anything else in my rig but for a rod it's not exactly the best option. It is very large and heavy and it uses a lot of power. First gear is above 3 to 1. Convertors, shift kits, and performance mods for the Allison are priced in the stratusphere. As far as I know there isn't anyone producing a stand alone PCM for the allison and nobody is offering Allison PCM reprogramming. The Allison 6 speed is coming and mods for it havent been done yet, it adds another overdrive.

The 8.1 in a nutshell is a LS'ed BBC with the advanced tech but a not so "awesome" truck style torque intake. That is unless you consider 455 lbs./ft. factory torque awesome. It has the 454 bore with a longer stroke and rods. It is a 496 and isn't at all like the 502. It has LS style fuel injection, heads (yes cathedral ports), altered firing order, crank triggered ignition, coil near plug, remote thermostat, new block casting etc. Thankfully the trans mounting bolt pattern and motor mounting are the same. It was a complete redesign and no parts interchange with the older stuff. It's an excellent engine but you're NOT going to slap some Dart heads and a Accel intake on it. There is a company that produces aluminum performance heads and an intake, that would be Raylar. Again price is high. The only reason there's much at all availiable for this engine is because they are the new Mercruiser V8 used in power boats. Cams and headers are readily availiable from a few sources. Check out Tbryn's (spelling) website for it's 8.1 section. ECM tuning is widely availible since it is like the smaller LS trucks and cars in that respect.

What Bo185 said about the trans conversion applys double. Trying to convert an Allsion from 4x4 to 2wd would require a complete disasembly and output shaft swap along with the shorther tailshaft housing. Finding a good trans guy willing to do this will cost you a lot, no make that too much money. Like I said use a "normal" performance tranny and stick shift ECM/wiring.

These engines can be found on Ebay from time to time still in the crate for much less than the entire drivetrain you've found. I wouldn't use that drivetrian in your rod. If it were me I'd buy one of those 8.1's off Ebay and do it like I've outlined or just build a traditional 502 and get more HP for my money and time.

If you go ahead with the 8.1 you should start visiting www.GM-trucks.com. Their 2500/3500 HD forum is the internet's 8.1 hot spot. Over there I go by Haulin' 8.1, we just opened a performance engine tech forum so you have a place there, lol. A buddy there and also on www.PerformanceTrucks.net who goes by TieRod has pushed his 8.1 powered 2500 HD into the twelves with NO2 and now has done a performance rebuild with the hot heads and intake. Now we're all waiting for spring in Kansas to see his new times. I've picked up a Whipple kit for my truck and a Duramax intercooler. I'm collecting the pieces for a blower set-up on my rig. I want a blower cam, heads to port, and big headers before I put it all together. Right now I just have a few bolt-ons and a Hypertech and the 7,000 lbs. crew cab 4x4 runs in the 15's with torque managment bigger tires and 3.73's.

Vernon

 

Thanks for all the info Manic- the main reason that I want to do this swap is the cool factor of a 50 year old truck that drives like a brand new one. After a little research I found that you are right with the tranny and it would be much better to go with a 4L80E that can be beefed up to handle the motor.
This truck will be a rolling ad for my business (butcher shop) so I want it to stand out and look cool. Thanks again for all of the help!!!