liked the cheapo soda blaster and saved that site.
Humhhh? I can see that larger o.d. tires and the longer roll-out would slow initial acceleration as, of course, it makes the rear end gears 'longer', in essence. But, can't see how such a change should turn into a bog. Slower, yes, bog no!
Carb'ed? Maybe you need to adjust the pump shot, shooter volume, etc. to accommodate a slower acceleration rate. More pump stroke and/or a slight larger shooter IMHO. Or, maybe a small accelerator pump issue like a leaky gasket or porous diaphragm.