ok i have a pre 80's Chevy 350 block in my car... i just tuned the carb (this was my first time) the most Vac i could pull out of my motor was 20 is this normal ... good or bad or what.... all i know is that before i tuned the carb the motor was jumping all over the place.... not that i'm pulling 20 on the engine vac the motor is smooth as hell i was like WOW! so is 20 normal ?

 

Normal.

Some may say high. Must have a fairly mild cam.

 

as far as i know its a stock cam

when i got the block it had the stock GM intake, stock vavle covers worn out vavle train so i don't really think it has a mild cam in it... the only mods i did to the motor was an edelbrock intake, holley 600cfm carb 1.5 full roller rockers, hard push rods comp cams lifters after market timeing chain. MSD 6AL box and hooker headers....

 

Okay, must be a "very mild" cam.

Such as a stock factory cam.

 

Must be nice to have vaccum.