[mustangman65_79]

I was reading up on vac sec when I got my 600 CFM holley, I found out that if the motor stumbles when the secs open, that it is too much gas, and basicly your flooding your motor out. Your secs shouldn't open when the car is in park, or netrual, only when moving. I found all this out when I thought my car had the same prob, just to later found out I just had a really bad vac leak.

U should be running a gap of .35 stock coil, max of .45 on a aftermarket coil. I run a .40 gap on my 302 with a 45,000 volt coil and 750 holley vac sec.