Yb2fast,
At the 2012 Byron's Challenge in Chicago, I finished 6th in the GT A-main with basically a RTR Kyosho GT2. My car was stock chassis, stock plastic shocks with kit springs, stock shock towers and chassis braces. The only things that I added were as follows:
1. Straight cut ring/pinion gears in the diffs
2. Ipanema Blackhawk transmission w/ center CVDs
3. Werks B5 engine with Werks 2013 pipe
So, you don't necessarily need to "bling out" a Kyosho chassis to be competitive/hang with the other cars. Yes, I was still rocking the stock dogbones on all four corners!!! I worked more on car setup and choosing the right tire shores for the track conditions and temps. I also don't go "balls out" in the beginning of long mains; just pace myself because there will be some racers that will tap out during those mains for mechanical/technical reasons.