Any & All suggestions appreciated. I have a 455 that has been balanced and blueprinted. Cam is a Comp Cam - 96-203-4. Intake - Edelbrock B4B. TA headers. As you can see this motor shouldn't be a slouch and it isn't. However over the past year I have been having carb problems. When I built and installed this engine about 3 years ago, I installed a brand new 870cfm Holley Street Avenger. After a little tuning and tweeking the whole set up ran great for a couple of years with minor adjustments periodically. Last summer I had it tweeked again and started having problems. Mainly the power valve would blow out. And no it does not backfire - never has. Since then I have replaced the primary power valve 3 times and the secondary once. I have also installed an aftermarket powervalve protector. Now I am to the point where I am uncomfortable with the car. Even though it is currently running fine - will it last? Will it give up on trips as it has in the past? I also talked to a local carb guy who said he has heard similar complaints about the Street Avengers and that it is related to the polishing and plating done to carb. And something is coming off and getting into some of the internal body ports. Anyway, I am thinking about a new plain Holley or Dominator carb. Is the 870 more than this engine can handle? Should I go to a 750 or stay with the 850-870? Thanks o No:
Most buick 455's came from the factory with 800 CFM Quadrajet carbs. I would stay with the 850 CFM range for your set up. The 350, 400 & 430 C.I. buicks came with 750 CFM Quadrajets.
