Got a miss......

[Silverback51]

......and it's driving me f*cking crazy.

So far I have replaced the MSD 6AL box, the tach adapter, plugs, and wires. Still misses. Get it up to around 3000 rpm and it's worse. Step into it a little and it's popping like a SOB. Oh, the tach bounces around like crazy. That's why I thought it was the box or the tach adapter. Nope, still the same.

It also sounds flat. Checked the timing yesterday and it took over 30 degrees of advance to get it to sound right, but it still ran like crap. No difference.

Pulled the distributor this morning to check it out. Wanted to make sure I had not sheared a pin. Nope, it's fine.

This is my first 385 series engine, so I'm still learning about them. Do they by chance have issues with the timing chains? I also remember reading somewhere that they can suffer from misfires if they sparkplug wires are close. Not sure what they meant by that.

Engine started life as a 460 crate motor. Original owner blew it up at around 2200 miles. He had it rebuilt and it's now got 5100 on it.

This started at the end of summer in that it would crap out a little if you got on it. Then it's just progressively gotten worse.

Any suggestions to look for will be greatly appreciated.

I have a new 460 crate motor sitting in the garage, and if I thought that would cure the problem I would put it in there. Just not sure if it's motor or electrical. Not sure if I have that much more electrical to change. I do have a new distributer in the box. Maybe I will change that out tomorrow also.

Thanks in advance.