I have a 1977 350 sbc I rebuilt this fall and winter (mild performance cam change as well as an intake change), and my concerns started out with a poor idle. The advice I got was to set up 36* mechanical advance and the turned into that the distributor could not get up 36* at an initial base timing set of 12*. Ok, so I put on some lighter springs, no change. Took off the springs, no change. So there is no way I am going to get 24* mechanical advance from my HEI. What is the issue that I am having? Should it not peg out at 36* without spring at a 1500 or so RPMs. I am certainly not getting that much advance with stock or light springs at 2800 RPMs. What should I try? Another issue is that now that I have pulled the distributor to get a closer look, I noticed a lot of play (1/8" or so) at the end of the shaft between the housing and the gear. Logic tells me that this could cause some timing issues with the gear potentially moving up and down as the engine ran. Is there a fix for that or is the distributor need to be replaced. The distributor looks clean and the like with little wear, but I am not sure what my next step is with this thing.