Put the GM hei back in, and replace the trans mount with the high mount... check how the fan sits in the shroud...it should just clear the bottom by about 5mm
This is massive propaganda marketing BS... there is no such thing...it is imposible to drop a random dizzie and have the correct advance at a given rpm and engine load for a given engine so the max explosion, (cylinder pressure) occures at a given piont for THAT engine between 12 and 18 deg ATDC +/- 2deg max.
Then throw in bore to stroke, compression , cam profile and fuel type as variations in timing...
Add to all that HEIs off the shelf are pre curved general ball park for EGR / pollution engines running very lean cruise ...
Further more, check out the current and recent threads on MSD ign..
And add to that multi spark is only for those who dont keep their ign system, leads, plugs etc in top condition, and only works at low rpms..
plus 3 colours in an engine bay is rule of thumb, a bloody ugly red box does nothing for looks other than bragging rights for when those not in the know are around.
PS I dumped an elcheapo GM type Chinese HEI in mine last yr, recurved etc, expecting to have no end of trouble.. knocked up around 8000 miles on it.
This is NOT one of the countfeit MSD units they mention on the MSD web site.
Only issue was a pin hole in the back of my water pump yesterday as I pulled into the workshop at morning tea...closest issue had... so far.