OK we have beat my Q-Jet to death by now but..... It is true I have found I have a stock Q-jet from a 1970 Buick 225 car that had a 455 motor. With that, what will I need to change or look for to make it a top performer on my stock 1969 GS 350? Other then adjusting with a screwdriver the mixture and idil this carb is as it was when swapped 20 years ago. I am having it rebuilt but also want to know what parts need to be changed. PS: With all my post about this car going flat at high RPM (Just before it shifts it seem to be starving) I received this question. Is my exhaust big enough? Well I think so? they are stock manifolds into a 2" or 2 1/4" pipe into flowmaster mufflers and out the back in a stock bend. I just checked the tail pipes are 2" outside diamater. I would think this dual exhaust system would be more then enough "flow" for a stock 350? Mark
30+ years ago I was having this problem with my 455 '73 Regal. I set the float level at 11/32" and it cured my stumble and the high rpm starving, and made a screamer of it in the process!! :3gears:
Yes, your exhaust is big enough. Here are the rod/jet specs on the two carbs: 1969 Buick 350 4-bbl auto primary rod 043 primary jet 070 secondary rod AK 1970 Buick 455 4-bbl auto primary rod 041 primary jet 067 secondary rod AY Although the 350 carb has a bigger jet, the 455 carb has an even smaller (proportionately) rod, making it slightly richer. Bigger jet=richer, bigger rod =leaner. Generally, a change of three jet sizes whould be coupled with a rod size change of one. (no, this is not the cause of your stumble.)
