Join Date: Jul 2006
Location: Lehigh Acres, FL
Re: Jets and Carbs
Thanks for the good ideas and info.
I went back to 4.5 power valve in front and removed the plug in the secondaries and put in 4.5 power valve there too, and upped my primary jets to #74s, and decreased the rears from #84s to #74s.
idol vacuum is 9", and the car now eases of of idol with no hesitation at all, much better than what it was. I still have "roughness" from 1500-on up to 2500 or so, maybe a touch more, and then it runs very smooth from then on up to 6500. The roughness i speak of is similar to the rough cam idol, but I would have thought that would disappear by 1500rpm max, but maybe I'm wrong, I never had this aggressive of a camshaft before, soo wasn't sure what to expect.
Also had a fouled #4 plug. replaced it, checked the resistance on the MSD wires which was good, and then checked the MSD distributor cap and found that the terminals in the cap were quite corroded. I cleaned them with some sandpaper, pup it back together with a new spark plug, and the misfire was gone. That of course helped alot with the idol.
Not sure if the roughness up to 2500 is normal, or if there is further adjustment necessary. I dont have the extra case to spring for a vacuum distributor right now, or I would make the change.
69 RS coupe, 4.11 Richmond gears, Muncie 4-speed, Dart SHP 406, 11:1, 4340 H-beam rods and crank. SRP forged pistons, Milodon 7-qt pan, Dart single plane and 215cc Pro1 alum heads, Comp XR300HR cam and roller rockers, Howard hydraulic roller lifters, Hooker 1 3/4" Super Comps, Quick Fuel 750 carb