Gentlemen - long time lurker, first time poster. I find my search for information often brings me to this forum... I'm dealing with an issue I need advice on. I'm running right around10.5:1 static compression on a 383 stroker, maybe slightly less. Total street motor... 64 CC aluminum...

Can someone provide a technical read on what direction I may need to adjust my breakerless Mallory HEI dizzy? First my engine: Cam is .487 intake .508 exhaust, duration 234*/244* @0.50 110* lobe separation 383ci, vortec 2.02/1.60 heads, 750 cfm Motor's suggested initial timing: 12*. Will not...

I have an 85 Series Mallory HEI wired to a HyFire 6A box. I'm adjusting the vacuum advance using an allen wrench inserted into the nipple on the vacuum module. Is there a good rule of thumb to use when doing this? Like, 3 turns counter clockwise from fully tightened or is it just major trial and...