can anyone give me more info on the S&S replacement for the magneti marelli ecm for my efi 96 ultra? Will it allow timing adjustments? or just fuel? I installed keith black pistons,and I need to retard my timing 4 degrees for break-in. Any info,or suggestions?
The S&S unit is a good upgrade from the MM EFI but a converting to a carb would be better IMHO. Not sure why you think retarding timing 4* is necessary for break in though; I think you will be fine if you follow a good break in procedure. Done properly, the rings will seat in about 25 miles.
There is a good break in procedure on here some place . I think it goes like this .
Third gear take it up to 60 miles an hour then off the gas and coast back to 30 miles an hour . do this only in third gear about ten times .
If the cylinders where honed right it should seat the rings really well. I did this when I rebuild a 350 short block chevy. that old truck would pull.