Fast idle

[427TJ]

Well I couldn't find any obvious vacuum leaks--all the vacuum caps and hoses seem fine. The throttle shaft seems tight as well. The carb may very well need a total rebuild as it's been on there since 1967 and logged over 105,000 miles. I was just wondering--would the avgas have anything to do with it? It idled normally until my second or third tank with the 100LL mixed in, then this 1300 rpm thing started. Oh, and it's also slow to fire after shutting it off warm. During a hot re-start at a gas station, etc., it cranks for several seconds and then stutters to life and then runs fine--at 1300 rpm.

I know they're kinda' pricey but I was looking at the bolt-on Edelbrock Q-jet replacement carb as a possible fix rather than go through the potential agony of getting the Rochester unit rebuilt properly. Any advice on that?

Thanks again guys.

Bill