timing/tune up problems

engine is a 70 cast 318
bored .030 over
4.00" cast scat crank
scat I beam connecting rods
kb847 pistons
302 ported heads w 360 valves
Comp Cams Flat Tappet Mutha' Thumpr Cam, 235i/249e duration @0.050lift, .497i/.483e lift 107 lobe seperation

lol I'll tackle the cam bushing and lower, does that mean i need higher initial timing then? to get 34-36 total i would need 18 initial???

carb seems dry and i've tested for vacuum leaks with no increase in engine rpms, vacuum gauge reads steady 17 at 1000rpm idle