Whirley,
You won't see any improvement in top speed by changing to a taildragger. The nose wheel is drag but relatively insignificant compared to the wing. Would you believe that most of your drag is both flat plat and parasitic caused by the wing and stab? In addition, the intersection of the wing and fuselage (and stab and fuselage) creates almost as much drag as the whole wing! Check out the pylon forums for in depth explaination.
Don't be discouraged though. Once you fly with a tailwhell you'll never go back. 3-point landings and ground-loops will make the training wheel gang nuts! Seriously, put the tail whell on and beat up on the other trainers at fun fly events with your new short turning radius.
When we were scrapping together a "trainer" for my brother all we had was an Avistar .40 fuse, Planet .40 (pattern type) wing, and the tail feathers off of an Extra. Man did that thing haul butt! It was a lot of fune but ceased to be a trainer.

Chris