Well in my opinion its all about a combination so there are many roads to success.

In my experience good results have come from high compression, lightweight engine components, vacuum pumps and certainly not least quality torque converters and transmissions.

I also feel that strong pushrods, quality rocker arms and with a roller cam stout spring pressures are important.

While it can be expensive I think Andy F has shown that money spent with folks like Wilson can be rewarded.

Of course all of this would be tempered by what do you want to do? Just go fast, run brackets, indexes, small tire, NHRA classes etc.

Good luck with it!