I just touched off my 429 with a 6AL and I'm going through the same aches and pains. It feels like its dropping off a hole or two when you slowly roll it on from idle to 2k+- then O.K? Seems to be workin way too much to run. Cam is run in for bout 1/2hr @ 2k. I changed plugs, wires, cap and rotor, checked TDC on new balancer again, checked cam degree again, swapped out carb.....The 6AL was from ebay...another ebay disasteer!!! I'm consisering shelling out for a new 6AL on sale at summit now about $20 off.....
Open to any suggestions!