Dear Zeke;
You have the piston MFG make the compression you want based on the size of your heads combustion chamber/bore size etc. Stock is about 40cc with the "848" a little smaller & you will need to measure this.
Ten to 1 is about all you need go with the forged pistons and 252" displacement.
The M-4F/261(grind) cams are great for the pre- 1955 engines which were 85 Hp. but won't do much for the later (55-62) ones which is why you need the F-290.
"Stall speeds" are of no concern here as the SBC V-8 engines idle at 8-900 RPM+/- from the factory using the Powerglide transmission.
Ballancing this engine is a good idea as Bryan points out.
Good luck.
