what can i expect from my 360?

what can i expect from my 360?

Here is an old school build up dyno'd that should about meet your level. Due note the comp ratio is a 10-1 vs. your much higher targeted ratio.

360 rebuilt with 10:1 compression flat top cast pistons, original crank turned .010"/.010", rebuilt factory rods. Factory windage tray installed. 2.02" heads with competition valve job and ported to flow 260 cfm. Edelbrock RPM intake, port/gasket matched. Holley H.P. 750 (.076" front, .080" rear jets). Large 1 3/4" primary tube headers. Comp Cams 305AH-8 camshaft with .525"/.540" lift and 305/312 degree advertised duration, 253/260 degrees @ .050", 110 lsa, installed at 108 intake centerline. This motor is a brute for a street car and would only be considered a weekend blaster.
495 h.p. @ 6,000 rpm
500 lbs. of torque @ 4,500 rpm

Taking a look at your build, I think you'll make it. I myself would not use a Magnum head. For an iron head, it would be the W2 or LP Commando, and in aluminum it would be Edelbrock heads. All heads would need some work done. OE heads would need the full porting plus. I do not know if it is worth it at that point to due the OE head.