Should ported or unported vaccuum be used for vaccuum advance? I have it on ported now. (Lower port on a q'jet) I am using a HEI distributer and the motor has a moderate cam. I do not know the cam specs at this moment. What should I expect for vaccuum using a vaccuum gauge? Also the timing mark appears to the passenger side of the degree marker and will not fall in the relm of the marker. Any advice would be appreciated.

I prefer full manifold vacuum, for improved idle stability, idle and low-speed traffic cooling, throttle response, and steady-state fuel economy. You didn't mention what engine you have - are you sure you have the correct balancer and the matching timing cover (pre-'69 vs. '69 and later are different) and you have the timing light pickup on the #1 wire, and wires indexed correctly in the cap (#1 tower is the one immediately clockwise from the window)? Is the index line on the balancer directly in line with the key slot or is it about 10* counter-clockwise from the slot? Need more info to help you. graemlins/thumbsup.gif

I tried full manifold vacuum and it stalled the engine right away. Would I retard the distributer to get it running with full vacuum? The motor is a built 350 (I973 I think) decked etc., heads are 882's reworked, Performer intake. Supposed to be in the 400 hp range. I assume that the balancer and cover are correct because the motor ran extremely well in a vette. Not sure about the balancer key way and the timing mark position. Would the 69 or newer be the one that is about 10 degrees apart? Can this be determined without taking it apart? Timing light and #1 plug is correct. When you say #1 tower is clockwise from the window, what are you refering to?
Thanks John

If the current timing setting puts the balancer index mark on the passenger (retard) side of the timing tab with the vacuum advance disconnected and plugged, either the balancer index mark is wrong, the timing tab is wrong, or the timing light pickup is on the wrong wire, and connecting the vacuum advance to full manifold vacuum should cause the idle to speed up, not to die. The '69 and later balancer is the one with the index line about 10* counter-clockwise from the keyway slot.

The distributor should be oriented as shown, with the #1 wire tower in the cap and the wires indexed as shown.

http://img.villagephotos.com/p/2002-2/13522/dist2.jpg
graemlins/beers.gif

Thanks John, I'll check into some of the points that you mentioned. The obvious things like wire sequence, #1 plug for timing light are correct. I'll check the balancer vs the timing index mark. I will also try full vacuum.