Set ups for grass drags?

[kuvasz]

Anybody have any good ideas for a gear combo for grass drags? I've still got my 38 tooth on the bottom and I was going to change my top tooth to a 20. my 1:1 is 112mph and full overdrive is 124. i'm hoping to see around 115-120mph in 500'. when I tested in late spring with a top 25 tooth I got 105mph on the gun in 500'. I would think I could get more traction on the dirt?

i'm going to install some quick connects and I've bought a cooling cart.

any help would be appreciated .