Join Date: May 2009
Location: Pacific City, Or
stumped on tuning
hey fellas, i'm looking for some help with tuning my 66' impala with a 77' 350 and powerglide. when i got the car it was running rough and advancing the timing helped along with some new plugs. recently i installed a new vacuum secondary holley 600 which also helped some. i had it running pretty good then, but i could tell the timing was slightly off in certain points of the rpms, specifically low. yesterday i installed a new msd streetfire distributor and a new set of plug wires and it would bog at low rpms and ping at the high end.
i put a larger accelerator pump and larger jets on the carb which helped in the low end, but the mid range is rough and it still pings on the high end. i've screwed with the timing and vacuum advance and still not improved the situation much. there's no vacuum or intake leaks anywhere. compression is 149 to 160. it does have some type of cam and a weiand stealth intake.
so, what do you think? any suggestions? intake sucks? timing out of whack? is it all related to the powerglide's high first gear? thanks for any help--i'm out of ideas!!