MY bet is it is not ign at all , the ign works clean in 1st gear & the ign cannot really tell the difference between 1-2-3 gear ,other than the load is slightly higher in the higher gears which would indicate a plug / wire / cap problem
Before you spend a dime we need to diagnose this . throwing $$ at stuff may not fix anything
First which ECU do you have , is the advance plate sicking in the dist, is the pick up gap set ? Do youhave a fuel pressure gauge you can connect to be sure it is not a fuel issue ?
I used stock Mopar parts , stock dist reworked , Chrome ECU & Blaster coil , I was shifting at 7200 rpm with no issues .
If you are going to throw $$ at it the MSD is twice the cost of Crane or Mallory igns & MSD uses expensive chips for the rev limiter unless you get the digital version . The Crane & Mallory just use a settable dial to set rpm limit .
