I am having all kinds of fits with my four-twenty-something big block. This motor is in a 1970 2X4 3/4 ton camper Special.
What I am having an issue with is missing badly off idle. I just found the vacuum advance module was bad, so I replaced it. I took the timing light to it, and the total advance was around 40 degs! That isn't working. With out the vacuum advance, I get about 10-15 degs of advance. Currently I have the timing set to about 5 degs BTDC.
What should the base timing be? What should the total advance range be? Is there a way to adjust the Vacuum advance?
Thank You Jody