i waz told would me 1mph an hour and stop bucking i have gp1300 with impellar1319 and pump seal dont like getting thrown

Dude, delete your other 2 topics.
If you put the 800 grate on your 1300r it will give you a little more top speed in the chop but it will suffer a little holeshot, compared to if you were to put the riva 1300r grate on, it will give you better holeshot and performance in the chop, but may shave off a little topend. Just what I have been hearing, I am not sure though, search for ISLAND RACING TOPICS. He has done some testing on this topic you are talking about and the answers are all there for you. Good Luck. Mike