David Green

I was looking for information on the 5 speed transmissions from full size mid to later 1990s Chevy/GMC trucks and their interchangeability.

Specifically, I found for sale a 1997 Chevy 1/2 ton shortbed 2WD (aka RWD) extended cab pickup that has a bad 4.3 V6 with a 5 speed in it. I have a 1998 Chevy pickup of similar description but with a 5.7 V8 automatic transmission. I was looking into swapping my 5.7 into the other truck. I presume that, physically, the transmission will bolt up to the V8 but is the V6 transmission the same as a manual transmission used behind 5.0 or 5.7 V8 engines in the same series of trucks or, if not, is it up to the task of transmitting the power/torque of a V8 - especially if I am towing a travel trailer that weighs 5000 lbs or so.

I am hoping someone sees this and replies.
thanx in advance.

David Green

I have a question about the 5 speed manual transmissions that were (and may still be) used behind the Chevy V6 engines in (specifically, the later 1990s) Chevy/GMC pickup trucks.

Are they the same transmissions that were used behind 5.7 V8 engines? (Or were 5 speeds not available in 5.7 V8 equipped trucks?) If not, are they up to the task of transmitting the power/torque of a 5.7 V8 for a "lifetime" of use in that application? I will also be towing a travel trailer that I am sure will weigh, with everything in it, over 5000lb (if not closer to 6000lb)

The reason I ask is that I have been offered a 1997 or 1998 Chevy 1/2 ton s/b ext cab 2WD truck that has a worn out V6 with a manual transmission in it. I want to swap in my 5.7 from my 1998 2WD pickup that has an automatic transmission in it. Now, I could, alternatively, swap in the automatic transmission but it looks like it will also entail a transmission tunnel, carpet, steering column and probably other changes to make it work. I was just trying to get away with not doing all the extra stuff.

Can someone help me out on this one?
Thanx

Irish_alley

GM had a nv3500 and a nv4500. the nv3500 was used in light duty trucks and the nv4500 was the heavier duty ones. the truck you describe i would bet has the nv3500. it can handle a 5.7 but it cant handle the abuse. the HM290 and 5LM60 were the earlier light duty trans and were replaced by the nv3500.
the 3500 was only rated for around 300 ft lbs
the 4500 was used behind many cummins engine and there putting out 400+ ft lbs

David Green

Thanx for the reply Irish -alley.... My gut feeling is as you said it.... I do have an older NP540 five speed transmission from a three ton truck. I knw that it has not rear mount on it and needs some special mounting adaptor made in order to use it .... as well as some kind of adaptor to make a speedo drive function with the computer .... possibly a custom setup for the U-joint adaptor and a few other considerations .... I am saving for an earlier truck that I will probably prioritize though.