What do you think of this build

The really low cost Speed Pro's are still down in the hole almost .050" with a compression height of 1.637". Better (not great) CR but no quench.

The Speed Pros that RRR listed are .015" further down than the KB232/362's (.015" lower compression height) and it will take a fair amount of block decking to get a quench height of .040" or so, AND if you do that to get the quench height right, you will have a a static CR of 10.7. So, if you do quench with the Speed Pro's for regular, runnin' around street use, you're pushing well past the conventional wisdom of staying at 9.5 or less for iron heads. So then you don't deck the block to keep CR in bounds and give up the quench effect.

I like to go for the quench effect since first doing one many moons ago and not having detonation with a 10+ SCR iron headed 351C, and the KBs look to have been purposely designed so that you can get the quench distance right with a couple of different ranges of CR, one of which is a pump gas CR range.

With the magnum heads, I think you need to be going for the KB232's, not the KB362's. For the 362's, look at the pix and see the raised pad near the valve eyebrows? I think those are supposed to be for the open chamber heads, to fill up the flat open area in the combustion chamber and form the quench in that area. Your magnum heads are flat there and I believe the smaller raised pad of the 232's makes quench with the flat area on the magnum heads, with a specific head gasket thickness. BUT, I am just surmising on those details; you ought to call KB and do your homework and not listen to me 100% on that aspect; I am just entering 360-land for the 1st time (planning a 360 build with magnum heads too).....I need to find out myself how tall those KB232 quench pads are and how they work for sure with the compression height and gasket thickness with the magnums. (If they are too tall, I just have them milled down.)

It looks to me that the KB232's will make an SCR of around 9.3 with a .04" thick head gasket and 63 cc combustion chambers. Looks like a good place to be.