408 dyno test

OP says timing is 35@4500, shouldn’t be a big problem with that.

Non-working vac advance is a non-issue, as it does nothing at WOT anyway.

My curiosity on the heads was more along the lines of them perhaps being 318 heads.
More power below that is where I went with that.
I do not see any components that make big power in ootb form listed. Performer intake...stock heads with unknown valve job and valve. I assume the cam is .441 aka .420 lift after all the bad angles. Whichever head...
..To me.. in this build..If the .300 lift is in the toilet...that's a lot of it.
Maybe I'm missing that you mean he needs some 302 heads? ;) jk
We're on the same thing..