305 heads on a 383 stroker?

[brothers69c-10]

Hi guys,
I've built small block chevy's beofre, but never a stroker. Nor have i put 305 heads on a 350 block. I have heard that you have to notch the block or something to make them work. I don't know. The heads are 305 HO heads with 1.86 intakes and 1.72 exhaust i belive, could be wrong on the exhoust valve size. They have 58cc chambers. Will this create to much compression to run on pump gas? I'm using the 400 crank and rods for the stroker. Flattop pistons and a somewhat radical cam, 4 barrel holley, alluminum high rise intake, the works. All of this for my 15 year old brothers 69 c-10
I guess my real questions are....
What do i have to do to put these heads on a 350 block?
and...
Will it create too much compression for pump gas?

Tell me what you think
Thanks in advance.