Since I'll be down over the summer due to the new arrival (XY) in early June, I was considering building something that has a little more umph over the summer .... OK a lot more umph. I'm considering a Nitrous Engine that I can still bracket race Normally Aspirated.

I have two good seasoned RB blocks ('66 and '68) and a set of Manley H Beams OEM (2.375/1.094) on each end. I'd like to survive 725-750HP NA with a 150-300HP shot w/ annual teardowns between seasons.

1. Aluminum Caps, Billet Caps or 4 Bolt Conversion?

2. Fill the RB block to where? Bottom of the freeze plugs or higher?