I apologize for a total timing 101 question. I have "been out of cars" for 20 years (since my teens) and have never REALLY done timing right anyway. Here is my question. I have an HEI in my 68 and understand the idle timing adjustment(rotate the dist to taste), and I somewhat understand vacuum advance timing (which I don't know if it's adjustable on my '75 dist), but, I don't understand how to adjust total timing. Is it with the weights or springs inside the distributor? Also, do you check total timing with vac line disconnected and plugged? Thanks, Jason
There's some very good threads that cover this thoroughly. Try searching for "ignition timing" or "distributor". I've responded to many of them as well, so you can use my username in the search.
Yes total timing is done w/vac disconnected. Most stock vac adv is non adjustable. Most stock cannisters will give too much adv also so it's good to check it. Mechanical adv is adjusted with weights and springs.