Iam thinking of adding nose cones to my trs drives. Where would the best place to look for nose cones , would it make a difference?? Iam running stock power twin 420's

Don`t bother, there`s no need for them until you are running mid to high 80`s.

Not true, I had 502's in a 38cig. After adding nose cones I picked up 2 mph

Yes, you benefit from a nose cone on the trs due to the fact the drive is not very hydrodynamic (sp) . I have used nothing but Hydromotive nose cones on my personal stuff and All my customers boats. They seem to perform quite well , you get more positive trim with the nose cone, without slippage of the prop. Tom