Super Six Idle Issues... Bit 'O' Help Please!

Find and fix the intake leak, probably at the head .
Verify your fuel level is correct.
Set your transfer slot exposure to a little shorter than wide.
Set the idle trimmers to 2/2.25 turns out. Forget setting the mixture screws to obtain the highest idle. That has never been right.
Set the idle speed with timing; don't move the curb-idle screw at this time. Do not retard the timing to afterTDC.
Reindex your accelerator pump per the instructions.
Roadtest it, at various Part-Throttle settings; do not floor it.
If it seems to take throttle ok, with no hesitations or backfires on the roadtest, then;
Put the linkage up on the fast idle cam to obtain about 1800rpm or a bit more; exact number not important. Now adjust the trimmers to highest idle speed. Then richen them up 1/4 turn and flip out the fast idle cam; don't touch those screws again.Your mixture is set right for cruising; or at least as right as it can be with the current parts.
Now for the idle;
first reduce the timing to get about 550 rpm. Next, adjust the Speed screw, (NOT the trimmers) for best quality idle, and not targeting the highest speed.It should not take more than 1/2 turn in either direction. By adjusting the transfer slots, you will not screw up the cruise mixture at 1800plus.
Finally, crank the idle speed to whatever you want it to be, using timing. I like 450 to 500 in gear, but slanties can idle a bit higher. I just like them ticking over sweetly at 450/500. Sometimes I idle them right down until every shot shakes the car, and the exhaust is thoop-thoop-thooping along.You can do this with a slanty because they fire 3 shots per revolution at 120 degrees apart every one of them.
Revisit the accelerator pump linkage adjustment.
Then roadtest it.
Get the idle and low-speed circuits worked out, solving tip-in sags or flat-spots as they may appear.
If it pings, that will be another post or thread.
Working out the timing rate of advance is another post or thread.
Wot is another.....

This has worked very well for me; your results may vary.