I'm not firmilar with the flatheads as we run clones, but I have a Briggs wit a big pipe sitting here that was previously used in a restricted gas class, what would need to be done to the carb to run methanol for a kids rookie class ?
The two holes under the jet need to be increased up close to the tec limit , which is .028 no go for the idle hole and .062 no go for the bigger hole. You need to get close on the idle , I like high 50's for the big hole. then you need to get or drill some jets , depending on which restrictor your using you may need a .054 , .056, .058, .060, with the biggest for the smaller plate. It wouldn't hurt to have the sizes on every .001 in between so you can leave the needle set at 1 1/2 turns out and tune with jets. You will also be advancing the ignition timing up 4 or 5 degrees to optimize the setup for alky. Jon