ok so i get my car going again turns out that whoever rebuilt my 289 used longer pushrods and when i installed my new cam it broke the lifter and bent my stud so i got that all fixed and i got the car running good it pulls real good on the highway but as soon as i hit 70mph on the speedo (no tach yet) it backfires through the carb like its lean but only at 70+ so its either a fuel/carb issue or possibly a timing issue but i mean more toward the fuel just cause i haven't really tuned it in yet but i also think it could be timing because of the 70* of overlap and at that high rpm its firing too early