corvette0869

Hello,

I plan on purchasing a 1968 - 1971 C3. At this time, I only have enough cash for a small block. When I'm able to upgrade to a big block, will I have to replace the transmission?

Any information for a beginner would be appreciated.

scrappy76

Manual or automatic ? My opinion, if your building just a nice daily driver and do not plan on drag racing, a small block tranny like a th350 will do just fine.

I just put a big block in my 76 and left the original small block tranny and rear alone.

jnb5101

those years all used a th400 for automatic transmissions-bb or sb. if it's a 4 speed, the transmissions are the same, but the bellhousing on the bb is for an 11" flywheel, the sb is a 10.5" flywheel. there are some variations (super hp used a 10.5" setup) but you won't find them in your car. you can buy a 10.5" flywheel that will bolt to the standard sb clutch from aftermarket suppliers. biggest cost is in the accessory parts when converting to a bb-brackets for the alternator, p/s, etc. probably be cheaper to wait for the right bb to come along.

BBCorv70

If you're tight on cash, not interested in restoration, investment, etc, you may be better off looking for a NOM big block. They're out there. Many other parts change when swapping from small block to big block, more than just the transmission.