MNBelv57
Member
Hello all, haven't posted in a while so I hope everyone is well and enjoying their cars. I hope someone can help with a frustrating problem I am having. I have a 72' convertible with stock 302 except for headers, dual exhaust Petronix conversion kit with Petronix coil and 8mm spark plug wires. I had the stock intake with two barrel until recently when I changed to a Summit Stage 1 intake which is described as a stock replacement for a four barrel car, and a Holley 4150 600cfm carb. I had the carb. since the 80's and got it used from a friend who said it was off a Chevy 350. I had this carb. on a Weiand Action Plus high rise intake some years ago and when some friends tuned it the car ran really well with great throttle response and plenty of power for a stock motor. For some reason it started running poorly and out of frustration I put the old 2bbl. back. Like I said this was quite a few years ago. So, I thought I would try the 4bbl. again. I rebuilt it and put it on the car but it doesn't idle smoothly and you can really smell the unburnt gas. The plugs were getting badly fouled too. I adjusted the floats as per Holley's instructions with the fuel level at the bottom of the sight plug and also adjusted the air fuel mixture screws with a vacuum guage to get the highest amount of vacuum. I also adjusted the timing to 6 degree BTDC as per the cowl sticker tune up instructions and set the idle to 575 RPM's in drive (for auto. trans. cars). But it is still running lousy and sounds really anemic. Since I don't know the origin of this carb., I figured that the jets might be too large so I took off the primary bowl and found that both jets were #66, the power valve was #65 and the squirter nozzle was a #25. I called the Summit Racing Tech. line and gave all these specifications to the technician but he thought that the combo was about right for a stock car. I am a little stumped here and by no means am I very experienced at this but I really want to get this car running strong again so I can enjoy it. Any help is greatly appreciated. Thanks, Mario