This carb is on a 65 mustang with a 289. OK, threw the carb back on taking vacuum right off the manifold, (disconnected the transmission vacuum line and power brake line). So just the reading from the motor is around 16 to 16.5 and then once warm 15.5 to 16. Still runs smooth with both the air fuel mixture screws all the way in. I look forward to hearing from you thanks.
Holley 600 questions:
Hi I read the post you put up regarding setting the primary and secondary butterflies on a holley 600. Very helpful.
my original problem was seems like i ran out of adjustment on the carb, i closed both air fuel mixture screws and the car was running smooth like i did nothing at all. once i popped the carb off i saw what you were referring to. So I followed your instructions i have "the square" image on the primaries from the slot , and I did the light test to get the the secondaries opening to match. once i put the carb back on any recommendations regarding the air fuel mixture screws? I knew a lot about holleys until i read your post, you have more experience than me, so thought your advice would be valuable. thanks for the help. my email is firstname.lastname@example.org