Hi. I have '66 Buick Electra convertible with a 401 cu inch nailhead. The carburetor appears to be original and is a Rochester 4GC. I ran the car today with the air cleaner removed and noticed fuel leakage from several areas after I drove it a few miles. One leakage point was at the accelertor pump and there were at least two other leaks coming from other areas of the carb body. Not sure if the following information is important or not in regards to this issue, but I'm running 93 octane with a drygas additive and also often use an octane booster and a fuel system cleaner additive. As I menitoned already, the carb is probably original and therefore is 45 years old and most likely has never been rebuilt. There is about 121,000 miles on the car. I've owned it for just over a year. Any guidance on where to start in an effort to resolve this issue is greatly appreciated. One quick solution would be to drive it off a cliff (with me not in it), but I'll refrain from doing that for now. Thanks again, Bill R. Hanover, MD
Bill, No need to drive car off cliff! After 40 years the carb deserves a fresh rebuild. start with rebuilding the 4G carburetor, check float level too. Greg
Bill, do yourself a favor and replace the 4GC with an Edelbrock Performer carb #1406 (I think this is correct #). Anyway, use their 600 CFM Performer with electric choke with economy jetting and it will be real close right out of the box. I have replaced a 4GC with an Edelbrock Performer 750 CFM (to support some planned performance mods) recently and am still dialing it in. I had massive leakage issues with the 4GC that was installed by the previous owner once I started driving the car regularly. You could always rebuild your carb but I have personally had varied results rebuilding 40+ year old carbs.
If I were you, I would start with a good rebuild of that carb with good parts. They are available, but not real easy to find. I have built many with good results. Much easier and better than pushing off the cliff. Too many good carbs get tossed away, and big money spent on new ones. No offense to you intended Mark, you have mods in mind that will need different carb. If you decide to toss this one, I will take it and build it.
Rebuild kits for those are disappearing from Auto Parts stores. You can still get kits for them. I stock the good accellerator pumps, but nothing else. I might get 2-3 calls a year from someone with a 4GC carburetor. I think we rebuilt two in the shop in the past year or so, they are not very popular these days.....Cliff
The best upgrade I ever did to my nail, was to acquire and install a '66 only Buick 401/425 Quadrajet intake manifold and Rebuilt - Late '67 Buick 430 Quadrajet Carb....
...roads salted and winter's coming, hibernation time. If it were me, I'd be hunting parts for recommended Qjet update..Qjets popular and lots of knowledge/parts available. Backup plan: locate rebuild parts if spring comes before Qjet update...
