Out with the 340 & in with the 410 stroker!

You shouldn't be pinging at 36* total....what do the plugs say? You might need to go with a heavier spring combo in the distributor. I run 35* total, eddy heads, 91 octane, and the same springs you have.

A couple plugs [autolite 64] looked yellow/glazed with some specs, and it felt really touchy/boarderline rough at 3500 cruise well into the full advance.

Since I've lowered to 32* total, it's smooth and sounds right if you know what I mean.

My plans been to raise it a lil to maybe 34*, when all is right with cam/comp the SB wedge chamber shape dictates needing only around 30*.

What compression do you have with those aluminum heads and what chamber shape?