Hey Lance, I may get a chance to try out that 21+4 engine, our track work a deal to race a limited schedule, and we will be hosting The 2013 Nitro Challenge, again at Fearfarm, 2/20-24/13 Last year they had over 700 entries, can't wait. I will keep.you up to date my engine. Thanks again.
I ran my older 21+4 with 9901/41001, in my buggy,that thing halls ass!