Timing Question

I just started up my 318 that I added mild-ported 302 heads, Compcam XE268 with new chain, gear, springs, retainers, etc., and new set of Spitfire headers. Motor has Edelbrock Performer with 750 Holley, and Mallory dual-point distributor. Its in a 1964 Valiant with 4spd and 3.91 gears. My question is, what should I set timing at? Right now I set distributor where it was before the changes and engine roars like a bear and idles real nice with a slightly noticeable lope, but I'd really like to know if there is a recommended timing set for this setup. Thanks Mike