Lee, both the 250 and 292 are excellent platforms to build a performance motor. Obviously there is no substitute for cubic inches but each motor has its purpose.
Probably the best thing you could do is get yourself a copy of Leo Santucci's book "Chevrolet Inline Performance Manual". Besides the performance info there is a wealth of build up tips, casting and part numbers, and good solid advice on the late model inlines from Chevy.
The book is available from the Club and is advertised in the 12 Port News.
