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