newly bought '69 roadrunner motor issues?
 

Hi guys new to site & Mopars. Just got a '69 Roadrunner drive train 383 727 Torqueflite. it was in another vehicle but soon to go into a refreshed '69 Satellite. wasn't running & wanted to make sure all is well before pulling the drive train. So here's the prob, runs idles great, no hesitation when revving in park, as soon as I put in gear idle drops & runs rough then stalls unless I keep my foot on the accelerator to the point that I start doing a burnout. Here's what's been done, all tuned up, fresh oil & tranny fluid, new wires, new gas tank, new Holley 600. Dist is mechanical dual point, tuned w lite verified w vacuum gauge & bumped up a bit per Jalopy Journal guys. did the same before and after bumped timing. I was @ 8 advanced went to 12. I have an idea but wanted to here from the group without tainting the pond.