can anyone tell me if 13in of vac is alright for basically stock 350. 290 hrse crate 350 standard bore 450/460 lift 222/222deg duration cam. i have adjusted valves and among other things .replaced intake(fixed backfire) and it doesnt have vac leak anywhere and timing is right. i have brake booster hooked to fitting behind carb(on intake). ported adv and 400 turbo tran. hooked to full intake vac. any suggestions???? vac reading was took in park @ idle and it has 9in. in gear. seems low to me but it may be normal for this cam, also engine has 76cc heads; 1.94-1.50 valves.600holley carb vac secondary.all new. any info would be appreciated....