Rocker ratio and cutting pistons

[tlivingd]

I'm working on my 455 buildup but still needing some answers. At how much valve lift would I see an interference problem with the 10:1 sealed power forged pistons with a zero decked block, if I were to zero out the block?
I'm looking to hit 10:1 with AL heads and give 450 hp streetable and pump gas. also what rocker ratio should I be using? I have a set of stamped steel 75 ones and would rather not replace them however, If i need to I will and what ratio are the 75's I know a lot depends on the cam but I want to have the options open for any decision.

[70 gsconvt]

My block is zero-decked so the pistons are .003 in the hole with 68 cc'd 430 heads and Stage 1 valves. I run Poston's 113A cam, .491/.510 lift and 232/246 duration and have just over .125 clearance running TRW forged, dished pistons with no notches. But I've been told that I'm about as close as you'd want to go without notching. And it's most important around the edge where it's not dished.