If I get the forged KB 745 pistons and have the raised part machined even with the flat spot on the oposite side of the piston how many CC will the dish be that is left? Is the second lower step where the deck height is figured from? If not what is the height from the center of the pin to the lower step?

Also who can do this operation and what would it cost?

I looked up the piston, KB745.
It is for a small block stroker engine (408").
The compression height is 1.465" to the top of the piston, not including the dome part.
The piston is step/dished with an effective dish volume of 20.5cc.
There is no description of the step / quench dome height? You may have to call and ask?
I would estimate the quench dome is about 0.050" and maybe covers 1/4 of the piston? Volume of 4.00" bore and 0.050" depth = 10.298 cc. Assuming the Quench done is about 1/4 the piston top that would be about 2.6 cc (rough estimate) if the quench dome was milled off.
This would make the dish close to 23.1 cc.

Assuming this is for a 0.030" over 360 (4.030" bore) stroked with a 4.00" crank, and assuming the dish volume is 23.1 cc, with a 0.040" head gasket (about 9cc volume) then the compression ratios would look like this:
64 cc head = 9.48:1 compression
68 cc head = 9.14:1
72 cc head = 8.84:1

Note: this assumes a -0.012" deck height.

I am useing 52 cc aluminum magnums 4.060 340 block 4 inch stroke and will get the quench to .040 but I want to use both of the quench pads on the magnum style heads.

I am not haveing good luck finding pistons to do what I want for an affordable price. A year or two ago good pistons were around $550 a set, took me a year to save up some $$$ and now they cost even more even though raw materials are down labor costs are down and sales are slow. If they would hurry up and get e-85 here I could throw some flat tops in and be readdy to go.

I was thinking of getting rid of the secondary quench pad and carving an AFR design in my 53cc Magnum R/T's. I'm using the KB 745's and would by a custom before springing the $$$ to modify them,but maybe you can find someone that can do what you need for a reasonable fee?

Are your mag R/Ts angle milled or are the valve seats installed after milling and hanging into the chambers?

I guess the cost point would be if I can get the pistons for about $450 and get the milling done around $100 otherwise I guess I will have to suck up and buy a more expensive piston.

Yes,they have been milled to the intake 45 degree. Doesn't take a big cut to get there.

I can't remember the CCs and I was not sure if they were exactly the same and I am 2000 miles from the guy who did it for me and he is not good about shipping stuff.