i run a tsf2021 on a 20 honda it works fine. depending on how fast you spin the pump you can get between 7gpm and 8 gpm at 2700to 3400. if you have the motor already use it until you can get a bigger one. thats my plan at least.
Kory if you do alot of flat work get the tsf2021 its a workhorse. you cant beat gpm for flat work. if you already have the ts2021 you can over drive it to about 1750 rpm and get about 6.5 gpm out of it and still get about 500 hours out if it before a rebuild.