?Noise? problems?

[64Vair]

OK, I will try to be brief, yet still complete. MS1 v3.0 board with MSnSE. I am running a 7 pin GM HEI ignition that has been fitted to a 1962 Corvair.
I recently also put on a Mallory Digital (VI A) CD ignition box. The problem is actually better with the box than it was prior to the box. The way it is now, at around 4000 rpm to 4500 rpm, I get nasty noise problems, shift light goes on and off, car misses, etc. Not always, if it is under enough load, it is fine. Above 3500 rpm, if under LIGHT load, (like you are on the freeway, and start to go down a slight hill and have to lift to keep from picking up speed), it will flash the shift light, and miss slightly. A data log showed normal RPM, then 9,900, then normal, etc.
Now, the tach lead going to the relay box is sheilded cable. Then from the relay box to the MS is shielded, (yes, shield grounded only at one end!). This comes from the R terminal on the GM module, and goes to pin 24 on the DB37. I have the terminal E going to pin 25, and terminal B going to pin 27. Terminals B and E are NOT shielded cables. Should I run them as shielded also?
Here is another thing about the noise problem. The dash tach gets its signal from the Mallory unit. (B+ and C terminals on module go to switched +12v and trigger wire respectively). The Mallory unit provides 2 wires for the coil, that deliver 520 volts so no other wires go to the coil. (remember, I had this problem WORSE before using this!). The MS gets its tach signal from terminal R on the module, and the Mallory unit gets its tach signal from the C terminal on the module. When the noise problem happens, it not only makes the MS tach go nuts, but the dash tach does too. that makes me think the problem is between the MS and the module, and not elsewhere.
any thoughts appreciated. This does not make the car undrivable, but sure does slow it down in HARD acceleration!
Thanks!

[64Vair]

Just for general info, looks like I have mostly solved my problem. I had used a shielded cable for the tach signal to the MS from pin R on the module. And I had twisted the wires from pins E and B on the module going to the MS. This was done in the harness from the MS to the connector that went to the module. From that connector to the module was only around 6 inches, and there the wires were not twisted. I desoldered the wires, and twisted them right up to the module. Well, my problem ius all but gone. I tried to get the noise problem, and could not. I drove in a manner that would have definately produced the problem before, and it was fine. Then I did have it "hickup" once on me a tiny bit, so it is not completely gone but definately MUCh better than before. I think I will next reduce my dwell time. Don't know if that will do anything for it or not, but with my digital CD box I know I can get away with less dwell time than I have now.
Thank to all
Tom