SBF = Small Block ford. 289/302/351W etc. You can build a 351W as a 408 or 427 stroker that makes 500-550hp all engine on pump gas relatively easily these days.
No need to go TCP, though their stuff is nice. Properly modified stock type suspension can actually handle REALLY well. The Ford engineers that developed the suspension really knew what they were doing. Unfortunately, it was poorly implemented from the factory in order to save money.
Relocate the upper control arms, use the right springs/shocks/bushings....the stock setup actually has excellent suspension and steering geometry. The biggest handling issues Classics have is in the rear suspension. It takes some work to make leaf springs function well, but it can be done reasonably cost effectively.
Keep in mind too, if you ever want to race competitively in something like autocross, modifications determine your class. You put something like a TCP front suspension on....and suddenly you're competing against $200,000 race cars in SOLOII.
Who cares how much horsepower it has, all that matters is how fast it goes!
Untested 331, lots of suspension, chewing up corners.