Newly rebuilt 261 Chev with 235 head with stock intake, single barrel Rochester carb was running great until a 220 klm (100 mile) drive to break in the engine. I went with two others to a cruise both Fo@#’s1 was a 32 1/4 ton PU with triple carb flathead and a 61 Fairlane 289 v8 neither could leave me behind it was very strong.
Suspect that I developed a vacuum leak, it runs very rough at idle and smooths out and has a significant rpm increase if you cover the carb with either your hand or even reinstalling the oil bath air cleaner. Vacuum gauge now reads 14 to 17 with small needle movement it was 18 to 19 with steady needle. I will be doing a vacuum check tomorrow with a propane torch or maybe starting fluid. Question for the day. Is it a good idea to have gaskets above and below the phenolic plate or none at all?
