RPM Timing Question

Ready to Strobo time this weekend, should I have the RPM's at 600 or 1500?

Seems like I've seen both given at one time or another.

Thanks

For your '72, 1500 with the vacuum disconnected (and the hose plugged).

Thanks Rick, thought that was it, but then saw 600 somewhere....maybe in my dreams......it has been a long winter ;-)

The factory timing practice of using 1500 rpms is only accurate if your advance springs in the distributor are in pristine shape. I'd try it, but then recheck at idle. Your timing at idle (with the vacuum line disconnected and plugged should still be in the 10-14 BTDC range. If its significantly lower than 10, your advance springs are severely fatigued!

Jeff, they shouldn't be.....I believe I have the best dizzy in the world....after all, you just recurved it about a month ago ;-)

Then use MY instructions! The factory specs no longer matter with my recurve (oh, how short my memory is becoming!) 10-14 BTDC at idle!

By the way, I'm hoping someone else will recheck their timing at 1500 rpms and at idle... Without a rebuilt distributor, you'll find some pretty wild numbers!!! I think with mine there's a couple degrees advance. With an old dizzy, you could find 15 degrees advance in that range?