Timing guru's---ADVISE ME!!
The engine is a 390 Cadillac it always ran good,but had ton's of blowby and would just spit&sputter from stop to WOT .So had a total rebuild done all new internals and added a performance cam. 478-786 lift 268-274 duration 114-106 lobe center. I'm running 2 Stromberg 97's simultaneously,have pertronix igniter 3 ignition and headers. It ran like a 6 cyl!! Same thing from stop to WOT and even going down the highway if you stomp on it would spit & sputter then try to take off,but not too good. So I took it out yesterday and drove it a little,then advanced the timing a little--it helped ,kept advancing and the more I did the better it ran. Had to stop because Vac can was hitting manifold. Today I checked where the timing was. At 900 rpm with vac disconnected it was at 18 btdc --rev it to around 2000 ad goes up to 26 hook the vac up and rev it and it goes to 43. Starts fine even when hot and is not burning lean----should I leave it there or is that too much timing???I think if I would advance it a little more it would be scary fast. Oh, factory timing was 5 btdc .