1996 Chevy 4BT Swap
 

I have a 1996 Chevy K1500 I'm going to do a 4BT swap in. I plan on switching out the 4L60E for a 4L80E. I already have a 6inch suspension lift so I should have room to fit it under the hood. I picked up the 4BT a couple months ago and decided to tear into it and see what it looked like. I found the camshaft was damaged, the #1 piston scuffed the cylinder wall, and the #3 piston second ring was broken. The engine has numbers stamped on the caps so it's been torn into before. I am sending the 4BT and a 12V to the machine shop next Wednesday. Here is what the lobes on the camshaft look like.

Attachment 30609

Attachment 30610

It's a good thing I decided the check the engine out before putting it in my truck.

#1 Piston

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What trans adapter did your 4BT come with?

I was very unimpressed with a TH400 behind my 6.2L chev. (In a Suburban w/4.10 ratio) It was a slug, and didn't seem to put any power to the ground. The 4L80E is simply the electronic overdrive version of the same trans.

A few years later I ended up powerstrokes... and F350 (5spd) and E350 (auto) which re-confirmed my distaste for automatics with diesels.

IMO, a 5spd would be ideal, or in the very least the more efficient 4L60E/TH700 class trans. The TH700 has the benefit of not needing any electronics to operate.

Never had a problem with my 4l80's, they don't bark tires when they shift but they are extremely tough. Biggest draw back is they have a junk torque converter from the factory, get a low stall triple disk from someone like yank that makes a good product

Not discrediting the durability of the transmission.

The 4BT has somewhere in the range of 90-130hp and the TH400/4L80E series trans will eat up a big chunk of that. The 6.2L in my Suburban was a different animal after a SM465 swap and 3.21 gears. It suddenly had power and economy.

My 4BT was out of a bread van so it's rated at 105 HP. I plan on turning it up, I'm not sure how much yet. This builds focus is on mileage so I don't want to go too crazy on the power. My 4BT was mated to a Chevy 4 speed manual, and I got the adapters with it. I would prefer a manual, but this truck is already an auto with a push button transfercase shifter so my floor in the middle has nothing sticking up, and I want to keep it that way.

Might be a good idea to read up on 4BT conversions over over at:
Cummins 4BT & Diesel Conversions Forums


This guy used a TH700... but would have gone 6BT if he did it again.
93' Suburban Cummins 4BT swap - Diesel Place : Chevrolet and GMC Diesel Truck Forums


Mention here of the Dodge 47RH having better gear ratios than the TH700.
Real world mileage 4BT 1/2ton - Pirate4x4.Com : 4x4 and Off-Road Forum

Nothing says economical like a 6 inch lift and mud tires hahaha.

The truck will be slower than a stock 6.5 so a 6 bt would be a good idea and then use the 4l80 for its durability.

I got 22mpg in my 95 k1500 with a 6.5 and 4l80 but it was stock suspension wise

A 47RH was my plan B trans. Ya I know a lifted truck isn't very economical but I'm ready for anything above 10 MPG. I'd rather tune this engine for mileage because I'm building a 1995 Chevy 4-door for towing/power.

Nice perk with the 47RH is OD is the extra tall OD at .69.

I see it as the ideal auto trans because you can ditch electronics completely now that your engine is too. And its already made to fit together. :c:

I do like that it is mechanical, and I very well might end up running it one day. The 4L80E came in these trucks so it bolts all in like it should, hooks up to my shift cable, is clocked right for my t-case, and I already have a factory stand-alone computer for it. Downside is the torque converter stall (out of a 6.5) and I'll have to swap my t-case input.

And IIRC the lengths are about the same so I should be able to use my factory drivelines.

Is that a 6.2/6.5 van controller? That's already a big piece of the puzzle then :tu:

It's out of a truck, I think 1993

Ya, same one I mean.

But at the same time, I don't think I could live with a 4BT auto... ;)