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Looking for a couple of tips to help tune my 1970 SS 396 with TH400. The engine is basically stock (402 with .030) except for the comp cams 224x234, .51x.52 bumpstick. I would like to tune the timing and idle mixture using the "vacuum method" and I have a couple of questions.
1. Do I connect the vac gauge to manifold vac?
2. How much vac should I be pulling?
3. If I time it for max vac will it ping?
4. How far should I turn the idle mixture screws (QJet) each time and should I do one side first and then the other or both at the same time?
5. How much should the vac vary during this procedure?
6. How low should I set the idle during this procedure?
7. With an automatic do I have to do the adjusting with it in gear or can I do it in park as long as I am in the proper rpm range that it will be running at?
Thanks in advance. Kevin
1. Do I connect the vac gauge to manifold vac?
2. How much vac should I be pulling?
3. If I time it for max vac will it ping?
4. How far should I turn the idle mixture screws (QJet) each time and should I do one side first and then the other or both at the same time?
5. How much should the vac vary during this procedure?
6. How low should I set the idle during this procedure?
7. With an automatic do I have to do the adjusting with it in gear or can I do it in park as long as I am in the proper rpm range that it will be running at?
Thanks in advance. Kevin