Race Ported 270 vs Race Ported 28.5

[flarcer]

I have a Redcat Rally 4x4 onroad car that I use for topspeed runs. To date I have run a best of 51 mph with a stock Zenoah 26, DDM pipe and 33/27 and 31/19 gears, but I want 60 mph. I seem to be maxed out gearwise so I'm looking to make more power. Staying away from stroker motors and more towards RPM motors, ONB Race Ported 270 and 28.5 seem to be the way to go. Could you folks give me some advise, pros and cons as which I should go with? Am I in thr right direction? Is there something else in the $350ish price range that could get the jod done? Thanks

 

[Bigger the Better]

You may want to write ESP or ONBR and tell them what your after and have them mill your head for you.