Repalcement 4.3 Vortec Block

[kvkon]

After hours of head scratching I've found a tiny hair line crack in the lifter valley of my 4.3 MPI Vortec (2004 model Alpha 1) that's been seeping antifreeze into the engine oil. I have found a 4.3 Vortec in a 1997 Chevy pickup. Would that block work for me? How about the heads? I'd probably do a 20 thou over bore with new pistons and rings and new main, rod and cam bearings. My engine is low hour so I'd use my crank and cam shafts, timing gears, lifters etc.

 

[Furbird]

Why not just drop it in as an assembled unit? As long as it's fresh water only you shouldn't need to change the head gaskets so the only hard part that needs to be changed on the long block is the core (aka freeze) plugs to brass and swap over all your marine-specific parts to that assembled long block. Obviously you'd want to change out any external gaskets while it's out of the vehicle (oil pain, valve cover, timing cover, rear main) but if the engine is a runner doing all that work just because yours is lower hours might not be worth the trouble. If you're going to go that deep in it you might as well do a full rebuild with all new parts or buy an already remanufactured engine.

 

[Rick Stephens]

Either way works. Get a compression check, even cold. Will tell you a lot. Good machine shop looking things over will get you to the finish line with best combination.

 

[kvkon]

Why not just drop it in as an assembled unit? As long as it's fresh water only you shouldn't need to change the head gaskets so the only hard part that needs to be changed on the long block is the core (aka freeze) plugs to brass and swap over all your marine-specific parts to that assembled long block. Obviously you'd want to change out any external gaskets while it's out of the vehicle (oil pain, valve cover, timing cover, rear main) but if the engine is a runner doing all that work just because yours is lower hours might not be worth the trouble. If you're going to go that deep in it you might as well do a full rebuild with all new parts or buy an already remanufactured engine.

Yep the engine is a runner but it is a high miler and probably just about due for an overhaul. Wonder if all my accessory stuff will bolt up to the truck engine block?

 

[Scott Danforth]

Yep the engine is a runner but it is a high miler and probably just about due for an overhaul. Wonder if all my accessory stuff will bolt up to the truck engine block?

Slightly different block, however most should. There were some changes in 2003.

check with your local machine shop before you buy a core motor.