Small Block & Big Block Chevy Specific - 400 sb with main bearing from 350 ?

does anybody know something about this? a 400 sb with 350 main bearing, someone told me about this but i don't think this even exist, i've been searching and nothing was found this is PN from block 330817, it just says 400 sb made 73-80's, this person says crank can not be installed it just does not match, it seems main bearing are too small like if they were from 350 or something, there is maybe a mistake of parts there or a kinf of mess over there. anyway, any input?

400 had a larger main bearing than a 350. You can put a 350 in a 400 block with thicker bearings or spacers. You can put a 400 crank in a 350 block if you turn the mains down.

400 had a larger main bearing than a 350. You can put a 350 in a 400 block with thicker bearings or spacers. You can put a 400 crank in a 350 block if you turn the mains down.

what i meant was... 400 block with main bearing (where crank must be installed) from 350 i know this sounds kind of stupid, and dont believe this can even exist just wanted your opinion. so what this guys says, he can not install 400 crank into 400 block, this is senseless....

Im so confused

If you are saying that he told you it has the mains in it already and he cannot put the 400 crank in it, he might already have the 350 crank bearing spacers installed. You can certainly buy these spacers most any place.

It makes a big bore short stroke fun motor ! 377ci. Racers use to do it to be within guidelines of allowable engine size rules. I love me some 400ci small blocks.

If you are saying that he told you it has the mains in it already and he cannot put the 400 crank in it, he might already have the 350 crank bearing spacers installed. You can certainly buy these spacers most any place.

That makes sense, im gonna see it personally, thank you guys for replying.

Some Bow Tie 400's have 350 mains.

http://www.jegs.com/p/GM-Performance/GM-Performance-Parts-Bowtie-SB-Chevy-Sportsman-Blocks/956483/10002/-1

Al