454 4 bolt main or 2 bolt main

[454Chevy]

Do any of you guys know if the 1989 suburban 3/4 ton came wiht a two bolt main or 4 bolt main

[rmwick]

Not an expert, but the chances of being a two bolt on a 3/4 ton, if that is the original engine is very small. 3/4 ton is a work horse, my 99 454 has a four bolt with the big heads from Chevy which is their stock motor that year. You need the engine number and call a rebuilder or call your chevy dealer parts department and they should have an exploded view on their computer. I f your dealer only shows one 454 for that year they can tell you if it is a 4 verses a 2. I run a 427 blue printed at 13:1 compression in my boat on a two bolt main. So do not think it cannot do a good job being just a 2 bolt. Also on a 4 bolt down by the oil filter their usually is a cast ironplug about the size of nickle, that is usually a give away it is a 4 bolt. When I am looking at an engine that maybe a core that is the first thing I look for to see if it is a 4 bolt since you cannot see through the oil pan. Sorry for the long responce.

[454Chevy]

I dont think is the original engine but im guessing its a 4 bolt because it has alot of power and it also have big heads.

[rmwick]

Check just above the top of the oil filter on the engine block itself, may not be easy to do, use a mirror and if you see a screw out cast iron plug between the size of nickle and a quarter its a 4 bolt, but just because it is not there does not mean it is not necessarly a 4 bolt. But if it is there it is conclusive to be a 4 bolt main.