The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - setting timing in 68 c-10 with 250

jpert · 12-05-2010, 02:18 PM

DWmurry, Did you ever get your disrributor problem figured out? I have the same problem. I know an "old" GM man and he said they always set timing with a vacume gauge. Advance the timing until you get max vacume then back off distributor until the vacume drops one. When I do this the mark is at about 12 o'clock like you said. I have read that with HEI the vacume advance diaphram is 20 degrees or more and should be changed out with a 6 degree diaphram. My flyweight bushings are gone and I installed flyweights and bushings and springs from Mr gasket and that made it worse. I am still looking for someplace to purchase flyweight bushings to fit the original flyweights. Maybe you have the total answer!

12-05-2010, 02:18 PM	#15
jpert Registered User Join Date: Oct 2008 Location: Bismarck North Dakota Posts: 56	Re: setting timing in 68 c-10 with 250 DWmurry, Did you ever get your disrributor problem figured out? I have the same problem. I know an "old" GM man and he said they always set timing with a vacume gauge. Advance the timing until you get max vacume then back off distributor until the vacume drops one. When I do this the mark is at about 12 o'clock like you said. I have read that with HEI the vacume advance diaphram is 20 degrees or more and should be changed out with a 6 degree diaphram. My flyweight bushings are gone and I installed flyweights and bushings and springs from Mr gasket and that made it worse. I am still looking for someplace to purchase flyweight bushings to fit the original flyweights. Maybe you have the total answer!