HEI Ignition gurus Help!

[skidmark]

When I replaced my distributor with a new factory style I retimed the car and noticed when I revved the engine up to 3-3500 rpm it was advancing another 10 degrees.

Since I heard of other people having that 10 degree advance with an 8 pin

You changed distributors, then your 8 pin module started advancing timing by 10 degrees.
In your post you said it was running great till this distributor change.
I’m thinking it’s something to do with distributor? Or wires to it?
When you switched wire polarity to distributor, did you try and reset timing?

 

[67Dart273]

Like I said "ragged edge." Maybe the dist is not producing enough trigger, but the 8 pin doesn't require quite as much. Maybe the 4 pin "loads down" the output of the dist just a touch and for some reason it just can't supply enough. There are lots of us who have/ do run these 4 and 8 pins and they generally run great.

I've spent large parts of my life in and out of various types of electronics. I'm no "expert" by any means. But there are things that happen that you just cannot "box up" into a package and claim X or Y

Why do some timing lights "not like" MSD? That type thing

 

[7dart0]

Ok, I put in my original distributor same issue.
I'm getting 14.14 volts to the module same as my battery.
My ground from battery to module is 0V.

I rechecked all connectors to make sure of position and tightness.

I dont know what else to do.

Again I appreciate the help already given.