What is the best sprocket to gear ratio?

Hey Guys. I'm building a monster mower, actually everything is done except the sprockets which I have some questions about. The mower used to be a husquavarna belt drive hydro. And with a hydro there is no clutch pulley so I thought to myself why don't I make it chain drive! But I need to know what ratio would work best. right now I am working on putting on a 30tooth (5 1/2'') sprocket on the front and the same on the back. What kind of torque/speed would that get me? It used to go like 5mph with a 4'' on the front and a 3'' on the back. Let me know

Thanks

DieselDude666

If you are talking about chain drive from engine to trans, running the same size sprockets front and rear would be slower than the 4" engine and 3" trans that was on it. Hydros don't like being overdriven like you can with a gear trans, speeding up the pump too much can wreck it .

yah if your going to do that do stock ratios otherwise you will burn out the pump