Identified
I pulled the trans to put in all the performance stuff.
I took a look at the valvebody and found an OG14 code.
According to the *excellent* CK performance 200r4 rebuild book, this is a valvebody/trans from an Olds with a 307 V8.
So now I know what Ive got. Cant wait to mod it up and see how it goes! If I have any worry it is the part throttle / min throttle shifts, I think they may happen too quickly. we will see.