5mge rebuild crank and bearing Q's

[83 supra man]

ok, so I tore the 5m out of my 9/'83 cressida and after some research I've found that the main bearings are different in 82-83 5m's to 84-85 5m's? Since when has this happened? lol, really? I thought a 5m was a 5m was a 5m. The reason I ask is because the crank in this 5m spun the crank pulley and I have a good used crank from an 85 5m.
Also I plastigauged the mains and rods and found that they were both within the .002 and .003 marks on the gauge, I'd say .0027" which is close to the max limit of .0031"
So I'm wanting to turbo this block to hopefully 15psi so i'd like to build it the best I can to keep it from exploding. Now i'm thinking that there'd be nothing wrong with throwing in some new standard bearings and that should be good after all it probably wont last 200k miles or anything.
I'm going to toss in the better crank if the bearings can fit on it and see if the clearances are still within spec and maybe make some calls depending on what I find.

so anyone who knows first hand if the cranks are interchangeable to the blocks could let me know I'd appreciate it!

[msgsupra84]

If you want to go turbo, you might want to consider forged internals to handle the extra power and boost.

[84ptype]

Different oiling holes between early and late bearings...
order bearings to match year of crank.

If you plan on boosting it, take it in and have the crank polished and the machine shop order the bearings for you. You still have to give them the correct year of crank tho.

[83 supra man]

i've heard from a few people and read on some build posts that having forged internals aren't neccessary for these motors as long as you have a good ecu tune (megasquirt) and don't overboost. I really don't feel like shelling out 1200 on rods and hunting down pistons lol. maybe someday when i'm rich lol. There's this place called castillos crank service in california and i've heard that they do a really great job at polishing, knife edging, and lightening cranks for not too much money, like 500?

Locally there is this guy just down the street from me called kennys machine shop, he builds motors for nhra drag cars and trophy trucks, but he has a long waitlist (like three months out) unless you have $$ but does great work. so idk. Then there's always ricks cylinder head. or B and M machining that specializes in toyota's and L6's but his shop just recently burnt down...

I have twelve rods to choose from so I was going to pick the 6 lightest ones. Should i get them polished and shot peened? cryo treated? what the most i can/should do to have the best chance of them holding up without going forged?

[Road Ripper]

You have to match the bearings to the BLOCK, not the crank. They changed the location of the tab on the main bearings, and also moved the thrust bearing. I believe the cranks are all the same.

[84ptype]

You have to match the bearings to the BLOCK, not the crank. They changed the location of the tab on the main bearings, and also moved the thrust bearing. I believe the cranks are all the same.

ahh yes you are correct...spaced it. but the oiling hole to line up is in the block (along with the tab as you mentioned).

too many long days at work and too long since ive been inside an m-series

[BosmoB]

ahh yes you are correct...spaced it. but the oiling hole to line up is in the block (along with the tab as you mentioned).

too many long days at work and too long since ive been inside an m-series

At what point in time did the oiling hole for the oil pump shaft on journal #3 change positions? On my motor the hole is offset but my replacement bearings aren't. The hole in the bearing is actually obstructing half of the hole in the block. My motor is an 83.