I've heard alot of different things on what it will take to replace my 4.3L with a 350 In my 89 GMC 1500 Sierra 4X4 5 speed manual. Both are tbi, will I need new harness, clutch? What else? I am also putting in new exhaust. and know about motor mounts and fan shroud. Thanks to all

 

You can reuse your harness. The clutch will work IF it fits the 350 flywheel.

 

Thanx

 

I don't want rain on your parade, but last time I checked 350s are kicking out what? 180-190HP? The 4.3 Vortec puts out @ 265HP? Are you sure you'll be OK with the reduction in horsepower? (Since you asked.)

 

If it's a 89 4.3, he doesn't have a Vortec, and it's a lot cheaper to build a 350. Plus we don't know his situation, the 4.3 is prolly tired, the 350 may not be as tired. thats my 2cents. I say drop a 572 to into that thing.

 

Yeah, it's easier to buy more bolt-on horsepower for a 350, too.

 

Yeh, plus with 35 inch tires I will get better gas mileage with the 350 who'd figure?