1977 c10
350/th350
Headers
dual 2.25" exhaust
edelbrock 650AVS carb
edelbrock pro-flow air filter with paper element
So heres the deal, iv been running a 650cfm avs carb for almost a year since I got the truck. I also purchased a 500AVS and ran that for a few months but that might come later.
I did a tuNE up this year and thought I would dial in the carb a bit further. It's always had a bit of a ping at higher loads even with premium fuel. Iv leaned the cruise mode about 12% leaner and throttle response was very nice but pinging would start at about 10" of vacuum and would continue until secondaries woild open. To make a long story short I added all the fuel I could to cruise and power mode and pinging is still there. Also dialed timing back to 8 degrees.
So hear I am thinking and remembered issues like this with CV carbs on motorcycles. When u remove the airbox u adjust your carbs richerl because there is not as much vacuum suckig out the fuel. So out I went and put some duct tape on 3/4 of the air filter and low and behold, little to no pinging even after leaning the carb out.
So I feel these are my options:
Install 500cfm carb with pro-flow filter - this should increase vacuum though the carb at all rpm and load ranges
Install stock air filter and housing with filter-to-carb spacer - anyone think the stock filter would be too restictive?
Install a new filter and housing from a different year/make/model vehicle
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