I set my timing to 17 intial and 35 total by 3000rpm and it drives great. Only problem is after driving it for 2 days I checked the timing just to make sure that everything was the same and it was not. The car still drives exactly the same but with the dialback timing light it has an erratic timing mark and seems to show that it is around 22 initial, but the total is still 35 in by 3000rpm? What could cause the timing mark to change, eventhough the timing seems to be still at 17 initial? Yes, the distributor clamp is tight. Thanks for your help

DO you have an MSD box or similar?

No ignition box, just a pertronix flamethrower distributor.

I don't know if your situation is the same as this and I'm not familar with a Pertronix distributor. But, on an old 327, I had a combination of worn centrifugal advance weights that would bind, and weak/sloppy advance springs. The weights would stick and keep the timing slightly advanced at idle (2 or 3 degrees). Just enough advance to make starting a little difficult when hot. Full advance was always spot-on and engine ran great. After sittting and cooling for a while the weights would creep back to the normal stop and static timing would be fine. At least untill the next time the weights decided to stick. A good cleanup along with new weights and springs (re-curve kit) fixed my problem.....Jb

Mine did the same thing when I got it. It had a broken advance spring in the distributor. Also make sure your weights are not sticking. This will make your timing off at idle ( intermittant when sticking) but correct when running.
Johnny, you must of got that posted 30 sec's before me.

The distubutor is brand new, but I have made several spring and limiter changes when adjusting the inital timing. The weights seem to move freely, is there a good way to check and see if they are sticking?

I would pull the distributor and take it to a speed shop. Have them put it on a distributor machine. That will tell you exactly what is going on...Jb