sst60 prop set up

[total chaos]

i have an sst60 formula 3 tunnel but have a 55hp gearbox. when i had my old gearbox with a 1.85 - 1 ratio i was spinning my 12 3/4 by 22in prop at 7500 engine revs and then with my new gearbox i was revving at 8500 with the same prop but still goin about the same speed as the 55hp box is about 2.2 - 1. i have had some mods done to the engine now and i need a new prop to bring the revs down but still to go faster could any one tell me what size prop would be good for this. if any other sst60 racers hav tried these gearboxes or ratios before. any information would be good thank you .

[total chaos]

back ttt

[Fast Fred]

SST60 guys can't run that foot in that class, V4 25-26P with the trick washer

[total chaos]

we not as strict on our rules over here its any powerhead under 1000cc and anything else goes. thanks for that.