Chicken or Egg?

Are you ready for the dumb question of the day?

I usually do...Timing, then Carb, then timing, then carb... check timing, fine tune carb. The chicken.

Ditto...it ain't gonna all work out with just one adjustment on each. When you change one, it effects the other, so ya have to go back & forth a few times until i just don't get no better...then yer done.

Hey Joel, dose this method work for high performance setups(big block w/big cam/ carb) as well ,  especially if one did not know the specks on the cam etc. ?

The vacuum method works for any type of engine. Granted, an engine with a big cam is gonna be a bit harder to read steady vacuum on, but the end result is still the same...you want the highest vac. reading you can get.
Big cams can also be a little sensitive to the rocker/lifter adjustments...a little looser, or a little tighter can make a huge difference, both in vac. readings, and performance.
Another thing if using the vac. method for timing...make sure there are no vac. leaks to start with!

For those who have never seen/heard of this method, check out these two threads on the subject....some very good info here!

Setting timing

I hate timing lights

Thanks Joel .  As usual,  "Your the Man"  !!

Joel, thank you much for enlighting us who haven't see all of that info. Very, very interesting 

I used this method on my 72 LT-1.  I had to back off the  advance just a little as it would ping at full throttle above 3000 rpm.  I have a newish MSD distributor and I haven't had time to play with the mechanical advance springs.  Also, an LT-1 probably won't get as much vacuum as a regular small block.  I think I got it to about 12-14 inches.  (That's what she said!). 

Please remember that the vacuum method only makes your engine run best at the RPM it was at when you set it.  Ideally, you would have your engine running under slight load at the RPM you most often drive, then set for best vacuum.  If your advance systems are both functioning well and properly calibrated for your engine, this will be close to the setting from doing it at idle.

Larry