Just got my 51, no eng, 3 speed, torque tube rear end.

I've been offered a good running 230 out of a Nova with the 2 speed power glide for $300.

I have a Camaro disk brake rear end that I would like to use to save some money.

I'm not as interested in lighting up the tires as I am with reasonable gas milage, but would still like to do 70-80 mph comfortably.

The question is should I just go ahead and do a 350/350 combo? Buy some donor car for $500 and have all those extra parts?

Thanks
Any and all advice is appreciated.