factory installed engine

[bork81]

i have a 66 corvette coupe that someone put a 400 sbc in with stock 4 speed with ac .
i was wondering how to find out what engine it came with stock?
is there a tag plate somewhere ?
is there difference between small block vs big block?

any help would be greatly helpful.

[jcolarusso]

I'm pretty sure the car/frame/body won't tell you what engine it came with originally. You can decode the engine casting number & casting date to find out what car the engine was intended for, but not the other way around unfortunately. Check the link below. You can see all of the different engine/transmission possibilities the Vette had in 1966.

http://www.vettefacts.com/C2/1966.aspx

Absent a conversation with the original owner, it might be tough to figure out.