12 Second N/A Slant 6?

I have altered a set of rocker arms to yield a 1.6:1 ratio (rather then the nominal 1.5:1) and was curious as to whether the different valve lift afforded by these rockers would actually affect the total hp numbers, once installed. They would increase gross valve lift from .484" to .516."

If you are refering to the stock rockers they are more like 1.4:1.

1.36 has been measured in some cases.

Taking your .484/1.5 = .330 lobe lift x 1.4 = .462 gross valve lift.

.330 x 1.6 = .528