550 backfires when turned off, and sometimes when starting.

new electronic ignition system and new alternator conversion.

ran better prior to ignition system installation.

Tried to rebuild the carb with the Echlin kit, but about half of the parts did not fit.

Exhaust is darker than it should be.

Engine does not ramp up as quickly as it used to.....it struggles to speed up.

Not as much power as it used to have prior to changes.

12 volte negative ground and alternator are fantastic.

I doubt she would pull the 2 bottom 16 inch plow I used to have for her.  Levels gravel ok in 1st / 2nd gear with rear blade.  Used to do this type of work in 3rd easy....struggles now in 3rd.