360 magnum troubles
You might need to degree that cam.
Is it possible that you have a multiple key way sprocket and it has the cam 4*'s advanced or retarded?
A new balancer is good. The true TDC may not line up with the TDC marks on the balancer.
I was thinking THIS
I would recheck EVERYTHING
You can "somewhat" degree the cam.......enough to tell it's in the ballpark........right off a junk pushrod. Pull the no1 rockers off and "rig" an old pushrod so you can see what's happening, and with an indicator
Also use a piston stop and verify your balancer mark is right. This is the ONLY way to do this on an assembled engine
Also have you milled the heads, had valve work done? Maybe the pushrods are trying to hold the valves open, IE they have become "too long" due to head work.
The easiest way to "fight the carb" is to borrow a known good one off a similar "build" engine from a friend
You want lots of timing.....perhaps 15 BTDC at idle, and make sure it's advancing. Do you know what the setup in the mechanical advance is? Have you checked that it actually is advancing and not stuck?
Also monitor voltage TO the ignition system. If I understand what you have there should be 12V right to the coil and right to the ignition. If this is low or you have a wiring problem, it might not be providing decent spark
