[68cougar29]

Our 1968 302 2bbl /with Automatic Transmission timing was 6 degrees
We had a 351W cam installed,after that I had brake
issues due to low vac.
My Question is: What should I set the timing at?
The book says 6 degrees,but If it's a lot higher
wouldn't that increase the Vac?

 

[doctordesoto]

with the engine warm , put a vacuum gage on the car and advance the timing to to the besdt reading--no farther--if the engine will start without bogging the starter your ok--if not , retard it a couple of degrees and try it again--if it tends to rattle @ slight acceleration , try putting a vaccuum delay valve in the vac advance line(available @ napa)
doctordesoto

 

[Bad69cat]

Typically around 10 degrees is close...like the doc says you may need to play a bit. Your brake issue could be your booster
leaking too...best to check your engine vac with the booster out of the picture, then see if hooking it back up changes how it runs (ie leaking)