Lean burn is a very misunderstood ignition system!!! I was designed to make emissions regulations, Great idea but quite a few problems regardless of what engine it was on! all electrical connection were effected by corrosion, poor connection poor function! It basically had three timing modes; base (static), start up, and count up) all controlled by the computer attached to the air cleaner. That was put there to keep the electronics cool (outside air don't ya know).they had a specific carb. that just JETTED VERY LEAN (air fuel ratios will above 14.7 to 1) hence the name LEAN BURN. It would pull the fumes from the charcoal canister and use them also. The "count up timing was the main computer activated timing. the computer could add on so vehicle an additional 80 degrees at a steady speed. It had to start that "flame front" that early so by the time the piston got to TDC it (the flame started by firing the spark plug) it would be able to burn all the fuel ( remember they made it LEAN ) to make the engine have some power but burn "clean". Most dealers (their techs were not trained properly as that cost money to send them to schools) simple took if off. Hooked up the charcoal system with a vent valve/ purge valve system. Put in a dist. electronic or with points (electronic better for obvious reasons) that had a vacuum advance and a NON lean burn carb. That engine is bullet proof. They make all kinds of intakes ( 1 bbl, 2 bbl, 4 bbl, TWO 1 bbl's) intakes can even come in short ram or long ram style, headers, duel exhaust, cams etc. NHRA has a separate drag class for them with very high modifications. They can make in excess of 500 HP and live. the 225 even came from the factory aluminum block and heads. 170 cu in, 198 cu in and 225 cu in I would toss it all. Do some research as what kind of power you want to make, Make sure it is a 225 (by pass hose is about 3 inch long) Get a dist. with vacuum advance, Cam it if ya want, I would put at least a 2 bbl carb on it ( twi 1bbl's look better but a 2 bbl. easier to set up. and a nice exhaust. I'm an "old Fart" and have a bunch of stuff Books etc. on lean burn but not worth it in the real world.
