350 engine rebuild questions

[jcdubbu]

helllo everyone! i have a questions regarding the engine rebuild in my 1990 2500 4x4 (auto)truck. i have a 350 engine currently in my tuck that needs a lower end overhaul. recently, i obtained another 350 block with the cam, crank and pistons that has a good bottom end, i was told. i pulled the crank, pistons and cam out of the block i obtained and didn't see really any signs of damage to the crank or cylinder walls. my question is, should i have the crank turned anyways? where can i get tolerances on the crank and cylinders? will this second block even work in my truck? and last, where do they put the info to see if the crank has been turned already and if the cylinders have been bored? i see info stamped on the main and rod bearings but nothing indicating any work was done. i am wanting to buy a master rebuild kit but do not want to order till i have the correct information. i really appericate all the advice this forum has givin me. i hope to hear from ya'll soon. thanks

[2000CAYukon]

Originally Posted by jcdubbu

helllo everyone! i have a questions regarding the engine rebuild in my 1990 2500 4x4 (auto)truck. i have a 350 engine currently in my tuck that needs a lower end overhaul. recently, i obtained another 350 block with the cam, crank and pistons that has a good bottom end, i was told. i pulled the crank, pistons and cam out of the block i obtained and didn't see really any signs of damage to the crank or cylinder walls. my question is, should i have the crank turned anyways? where can i get tolerances on the crank and cylinders? will this second block even work in my truck? and last, where do they put the info to see if the crank has been turned already and if the cylinders have been bored? i see info stamped on the main and rod bearings but nothing indicating any work was done. i am wanting to buy a master rebuild kit but do not want to order till i have the correct information. i really appericate all the advice this forum has givin me. i hope to hear from ya'll soon. thanks

The Specs for 1990 350 are (all units are inches):

Crank Mains
#1 2.4484-2.4493
#2, #3, #4 2.4481-2.4490
#5 2.4479-2.4488

Rod Journals:
2.0988-2.0998

The only way to tell if the crank was turned is by measuring or looking the bearings that came out. What is stamped on the bearing? No reason to turn the newer one unless it is not within spec.

The cylinder bore is 4 inches. Again, measure to know if it was bored over or not. Pistons may be stamped. Again no need to bore over unless it is not within spec.

Is it a one piece rear seal or 2? Your 90 is 1 piece. You can use a 2-piece but you may have to use a difference flywheel/flexplate.

Good luck with your engine rebuild.

//2000CAYukon