I have a 1971 Charger 383 HP with a 509 purple shaft cam, .30 over, roller rockers, Holley 750, MSD 6AL,727 w/ a 3500 stall, and I am having problems with the engine stalling when put into gear. I have messed with the timing, the idle set screws and still no luck with it idling properly in gear. I have to drive the car with both feet (one foot gas, one foot brake)

I would plug the vacuum advance replace stock advance springs with light springs. then set total to 38. I would advance the cam to 102!

lets start at the begining.
first run on this motor?
or what did you change?

What RPM are you trying to idle at in and out of gear?

Initial timing?

Total timing?

If that cam is 248@50 initial should be between 18-20.

What AndrewH said. Just for a test I'd try setting the initial at 15-18 then the carb for a good idle in park then see if it'll hold it in gear.

This is what happened to me,and it ended up being the converter.
Just wanted to run it passed you. The converter was new and after a few days it would no longer idle in gear. The stator locked up.
Just a thought.

The PCV valve could be sticking, had that happen, it would idle in(P)or(N) but would die as soon as it went into gear.

My guess is not enough intial timing at idle and improperly setup dist. Bet ya

I'm going to go on a whim here and ask what type of airfilter are you using? I (dumba$$) had a restrictive aircleaner/filter on my first build many years ago and we stood there scratching our heads wondering why the car would stall *AFTER* we tuned it, timed it, etc... shut if off, put the cleaner on, started it, put it into gear and it died nearly every time.... well after this happening several times, we stopped to think what we were doing. Spent the $$ for a cheap mr.gasket airfilter/cleaner set up and bingo!! Problem solved.... have since upgraded from oh so long ago...

Just a thought....
Dave

If you still have the stock power valve,replace it with the correct one. I doubt you have enough idle vac to us the stock power valve. As others have stated distributor setup will be very important as well.

Thanks for everybodys input. I had a local speed shop set up the distributor and from what I remember he set it up to where timing is pretty much all there at start up. I have yet to get out to the garage and start messing with the car. Keep your thoughts and tips coming, I appreciate the help. Hopefully in the next week or two I will be able to get out and do some wrenching on it.