I've searched these threads high and low, got close but no cigar. My 1981 170hp V6 3.8L (model number J170STMRC1F) has bogging problems at higher rpm. Rebuilt carb, new fuel filter, coil, distributor cap, points, condenser. All plugs are the same, not fouled. Adjusted air/fuel to best rpm allowed better take off plane, but still loses rpm and bogs almost like a governor is attached after warming up a little. Get about 3000rpm at 32mph, i know i can do better. It used to run fine, then had this problem and they replaced the coil and it worked. Now I'm guessing the timing is out of whack. I looked at the timing marks but they are rusted out. Attached picture, mebbe someone knows what they are.Sorry for crappy picture.