1968 low vaccum

[Powell]

Hoping someone can give me some help/info here. My brother-in-law has built me a 302 motor for my GT/CS. It has a "mild " cam that claimed to be without any worries with vacuum.
Upon start up we find the intake vacuum is only 8 inches of mercury, Running a Fitech fuel injection system and it runs poorly at idle,but nice on the drive. Problem is the low vacuum is not good for the power brakes. Any thoughts of adding a external vacuum pump to solve the problem?
Thanks in advance for any help.
POWELL

 

[franklinair]

Summit Racing sells many models of supplemental vacuum pumps. 15"hg should operate vacuum requirements for PB booster & A/C vacuum controls OK.

Neil

 

[robert campbell]

Please let me know the cam specs. Eight inches at idle is way less than a mild cam should deliver. I think you have some other issues other than the cam. Timing or fuel delivery problems.

We need more info. What dizzy and what is your initial timing? I think we can sort this out.

Rob

 

[1968Cally]

Please let me know the cam specs. Eight inches at idle is way less than a mild cam should deliver. I think you have some other issues other than the cam. Timing or fuel delivery problems.

We need more info. What dizzy and what is your initial timing? I think we can sort this out.

Rob

I agree. At this point, I would not be worried about the power brakes or an external booster. I would be worried that there could be a flaw in the engine rebuild.