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Rddau · 06-27-2022, 10:48 PM

I have a 68 GMC 305 V6 with the above mentioned carb. I've had the carb rebuilt, as is the motor, and the plugs are almost white after just idling in the drive. Just curious what you all are using for main jets. I live in Minnesota, so about 1200' elevation. Backfires through the carb when hitting the throttle. Timing is fine. Vacuum is fine. Distributor advances properly.

06-27-2022, 10:48 PM	#1
Rddau Registered User Join Date: Feb 2019 Location: Alexandria, MN Posts: 7	Stromberg WW Main Jetting Recommendation I have a 68 GMC 305 V6 with the above mentioned carb. I've had the carb rebuilt, as is the motor, and the plugs are almost white after just idling in the drive. Just curious what you all are using for main jets. I live in Minnesota, so about 1200' elevation. Backfires through the carb when hitting the throttle. Timing is fine. Vacuum is fine. Distributor advances properly.