I have a late 70s low mile Qjet on a mild 355 Chevy, started out with 70 jets/52M rods, really small down idle passages. Bought the book ( great by the way), fixed the lean idle by going to 0.052 just on the down channels, and bumped the primary jets to 79s in several steps. Ran much, much better, but I notice it is still lean when below 45 degrees. It also runs a lot better if it's warm and rainy. Questions:
1. Damon Nickles posted a comment about and 80 jet and 50M rod being a good performer in a non-stock application, this seems really rich if I use the recipe as a guide. I believe it will be just right based on the butt dyno and general drivability. I have a cold air intake, restricted heat risers, and headers. Cam is 204/214 Crane.
2. This same carb ran just fine (with the 70 jets and stock idle circuits) on a L79 cammed 350 in a Camaro. Plug color = perfect, no big delta at WOT between it and a Holley 3310 vac sec. Could there be a leaning effect from the shorter cam? I swa this once on a V8 Monza with a stock cam and headers,huge diff between a single and dual plane intake. The latter was a lot leaner in various spots in the RPM band.
Thanks,
Stu
