I installed the pair of 3.5 powervalves.Vacum was measured at 5 to 6 and idle at 650 rpm .Checked timing .Oh crap! it's about 4° after.Tried to turn distrib got to about 2° bftdc and distributor housing (tach drive ) is hitting the manifold.Pulled distrib tried to move one tooth and then reingage the
oil pump, installed the hold down. I crank the engine .Man does it take off.Get out and point the timing lite 36° bftdc .crank back idle adjustment screws.Get it to a reasonable idle.I turned the distributor counter clockwise as far as possible ( hold down nut is difficult to get to now. burried under the tach drive. timing is set at 12° and advances to 32°,vacum is almost 8g and run on has stopped.It is sharp. Mallory HyFire VI has a programable start retard .I've programed 8°. I hate to mess with it But you think I may have jumped two teeth when I lifted the distributor? Don't remember the hold down ever being buried under ( so close that have to use a open wrench under the tach drive)