I am all over this problem. We built a 455 with a xR288 comp cam and it wont time. I have tried 3 different distributors, all HEI, 2 stock modules, 1 MSD module,2 coils, 2 distributor caps, 2 rotor buttons,3 different pick up coils, 2 different distributor gears, the engine had a brand new balancer, timming chain and gear set, I use an electric pump but I DID install the fuel pump excentric. I tried hot wiring the distributor to the battery directly. Nothing worked. The only thing that I think it can be is a bad thrust plate. I bought a grade 8 plate from Spotts and plan to install it tonight. I also had increadibly fast wear on my first bronze hear, 2800 miles. When the new one goes in another 1500 miles I plan to install the carbon fiber unit from BOP. This has been a nightmare. The wierd thing is I have a friend with almost exactly the same set up and his advances perfectly and times perfectly. This is very strange. I am also going to put my newest distributor on a Sun machine this week also.
69Firebird roundport/roller455
70Catalina 455
72Skylark Buick 455
89 Iroc 305 stock 192RWHP/263RWTQ
I cant leave anything alone.