I might be buying my dads pickup with the 4.3 V6 and the 5spd. And I know where I can get a Ls1 with low miles. I was wondering if it would bolt up or how much trouble it would be? Any help would be nice. Thank you.

 

you might wanna talk to tigerfan187, he jus replaced his 4.8 with an ls1. i also think someone did a post about swapping in ls1's into trucks. so try a search for that.

 

Its the 4.3 thats in the '93 with the 5 spd would taht be any different.

 

The SBC/LTI/4.3 bellhousing bolt pattern and I believe the spacing from the clutch/converter to the tranny are different. There are people who have bolted up TH350's and TH400's to an LS1, so I'm sure it's possible.

I doubt that the NV3500 would stand up to the LS1 for very long though. I know it's more money, but a T56 swap at the same time would probably be best and save you from having to pull the stock V6 tranny later down the road.

 

I know a guy thats running a 383 with dynod 450hp and he still has the stock 5spd. He is now rebuilding it and putting a bigger engine in there but he had the 383 in there for a good 3 years or so.

So im not worried about it not holding up im just worried about weather its going to bolt up or not. I want to make a good mud truck just for hitting the local mud roads. So I think this combo will work good. Maybe I should just get a 350 block but I want fuel injection, a little bit better gas mileage.

 

All I can tell you is that GM won't even put the NV3500 behind the 5.3! I have a friend who has an NV3500 behind a low compression 360 and a Vortech w/ 12psi, and his tranny is still working for now, but he isn't hard on it. He's also on his 2nd tranny.

I really think that you're going to have trouble with the tranny even with a stock LS1. Is your truck lifted or going to be lifted? Bigger tires? That will put even more stress on the drivetrain.

 

It will be lifted im thinking 6 inch suspension and 3 inch body and 35" tires.

Im also going to college and will be done in about a 1 1/2 so then I will have a little more money to upgrade all of this stuff. So all I need is for it to stay togeather for that long.