If you mean the AL heads are Edelbrocks with 63 cc heads, then the 5 cc's would ADD to the chamber volume, not subtract from it. So you should use 68 cc's not 58 cc's, if I am guessing how you are working the numbers. (And congrats for doing that homework.)
KB167's end up around .012" below deck for a standard LA deck height. With that and the Edelbrocks and the 1008 head gasket at .039" thick, I get a static CR of 9.25. DCR with your cam is 7.6. Decent for a street engine with decent low RPM torque, and quite a step up for a 318. Nice that you will a chance at some quench effect now. With the 2500 stall and 4.10 gears, you will need a larger tire budget LOL
Put on the 360 heads with a typical chamber size of 72-73 cc's, unmilled, with the same KB167's and head gasket and the SCR drops to 8.3 and the DCR drops to 6.8.... DCR is about that of a stock low compression 318 so low RPM torque will be about the same.