Hi, just picked up a 70 chevelle roller. it's a disc brake 4-speed 12bolt car w/ buckets the vin # is 13637 for a 2 dr, malibu, How do I find out what motor originally came with the car? the 12 bolt is gone so I can't tell if it's a bb rear. any info is greatly appreciated thanks Jim

No way to tell without build sheet, POP, or original owner. No such thing as a BB rear vs. a SB rear as such...only 10- or 12-bolt. Naturally, only 12-bolts came with the SS option but 12-bolts were available separately Only 3 small blocks in 1970; 307-2/200hp, 350-2/250hp, or 350-4/300hp.

Hi Dale, I was told years ago that big block rears had straps that hold the U-joint and U-bolts to hold the joint on small block cars. or is that a old wives tale? anyway the car is gutted the gas tank is in the trunk so I don't think the build sheet is going to be found. I'm installing a 454 and a turbo 400 anyway, just thought it would be neat to Know which motor originally came with the car. Jim

I may be wrong but I think the 12 bolt has the straps and bolts and a 10 bolt has the U bolts?
I know years ago I used clips to hold my joints graemlins/waving.gif