Ok. My car sounds like a bridgeport lol after changing the jets 2 60

 

but how dos it run??with a 600 it will idle heigh, the 600 is to big for a stock 12a but we can make it work.

 

Its running bad still but now its smoking black gray. It hesitates while load

 

i have a 600 and its a pain! needs adjusting all the time A/F mix screws 1 turn out and turn inwards till best idle. Mine usually is inbetween 1 & 3/4 for 23mpg highway

 

i have the 600 but it's from rb. i've always figured the issues some ppl have is cause they're using non rb holleys, idk. but i guess i can live with some issues more than others can. yes the 600 is too much for a stock 12a. u might can lean it out jet wise to work but the one rb sells for stock 12a is 465cfm.

ok, went back and read thru this again. what jets did u start with? don't know what increments the jets go but u may still be too rich. take it down to 50 and see how that does. rb also does away with the power valve with a plug. u might want to try that also.