I'm having an issue with my stock '69 C10. Since I've owned it it never idled right but beyond that it ran good but rich. A few weeks ago I swapped out the stock MV for a 250 MV. It runs much better but it seems to also run lean. I can leave the choke partially engaged and the engine performs better than with the choke off. I know I'm running a smaller carb but I'm surprised there would be that much of a difference. Thoughts?
