Carb work on Super M w/overbore

[BeanBoy]

My 1953 Farmall Super M has a 4 1/8" stepped head overbore kit in it. I bought the tractor like that, which is fine because I pull with it and was going to do that anyways. I am interested in mainly stock pulling. With that said, some slight modifications are ok. Modifications like an overbore kit, carb improvements and a little head work aren't really going to put anyones tractor into the enhanced/modified group. I like the "stock" pulling because you aren't butchering up the tractor at all really.
So anyways, my SM is "stock". I have read that a 560 carb lower half will bolt right onto my SM carb and that by doing that you get more fuel flow and a bigger venturi.
Another option I read and much prefer is to put a #29 or #30 venturi in my current SM carb and then enlarge the main jet and metering stem. This is an option I am more interested in as I keep the carb the tractor came with.
Any ideas how I can correctly enlarge the jet and metering stem? or maybe I can just buy that stuff somewhere? And where can I get a #29 or #30 venturi?
Beyond all that, I may consider some porting of the head, but that's a maybe. Besides all that, my SM pulls pretty good as it is, so I am not looking to enhance its power much beyond that.
Any help is appreciated.

[Bob McCarty]

Beanboy, Welcome to the Forum. Although I can't answer your questions, I'd suggest calling McDonaldcarb.com and talking to Morgan. He should be able to tell you about the availability of parts and hopefully answer your other questions.

Bob