Everyone keeps mentioning simple things. The Car already has an aftermarket electronic distributor. I have not had the chance to check timing curve rpm. Exhaust is stock manifolds, but aftermarket dual exhaust and Flowmaster mufflers (which I hate due to too much interior noise).
you have to elongate pushrod hole area, reason is they hit at max lift, i've done that for others . there's not much improvement for money spent, just food for thought. heads have to come off to elongate pushrod areas.