I wouldn't worry too much about gearing yet if I were you. You need to be able run cleanly and consistantly first. All the gearing in the world isn't going to help you until you are able to do so. What are you using for a motor and batteries? Are your tires worn? Have they been trued lately? Get it to handle first then worry about speed.
anothr tranny option that might be had to find these days worked real nice for my old wire cage sprint. robinson racing, (I think that is whole made it) used to make conversion tranny cases with top shafts, to change the old orrigional 2.25 stealth tranny, to either a 2.65 or a 2.18...the 2.65, (intended for the old rc10T, and eventualy adopted by A/E for the T2, in ratio anyway), made the car work awesome. I used a different spur pinion combo to duplicate the final ratio that I was running with the 2.25 set up, and found my car no axcellerated wit much more vigor, and authority. My motors also ran cooler as well, with less com wear under the same conditions as before.
so I think the 2.4 tranny would be a better choice, over the 2.25. I wish I had kept that old 2.65. I was running that sprint against car that were well over a pound, (yes a pound) ligther. Sounds liek a racers tale, but I bought the sprint from a guy who loved to make he cars look perfect, no worries about wight, the chassis was powdercoated yellow, and was welded out of 3/16" music wire except for the braces which were smaller 1/8"
Sounds like a old B+R I used to have....I wish I would of never sold that car back in 90....I still kick myself..LOL I had mine coated HOT PINK, had a black body and tail with a HOT pink stripe down the middle. Wing was black w pink numbers. It was neat to run it at night. all you could see was the cage....
There are still some of the r.r. 64 pitch gears around. If you can find them..I need a diff gear. I have a good top shaft and Idealer. But I melted the diff gear last year.
YEAH THAT'S THE TICKET! Thanks I wish I had kept mine too. I bought it painted up like the Sunoco sprint, with a big yellow #1 on blue paint.
they were heavy but that acctualy helped on small loose tracks, thye rest of the guys were running, losi and a/e buggies, with custom works bodies and cage, to save weight and for the suspention..I could acctually run the turns faster with the extra weight it stayed planted.