that is one thing that i havent tried yet.i do still trail ride the sled,so ill try that when i drag it, and put them back when i trail ride.got some testing to do today,i know i said i was gonna try one thing at a time, but i got carried away again,lol.i installed the 39 bottom gear, and robbed my wifes primary spring out of her 04 venom,lol.she has a ggg spring.i had a ywy spring.knowing that i was under by 200-300 rpm,and that gearing up would probably drop my rpm, i put that spring in to try it.i also have a gwg on the way.her sled has an under rev also. i will be changing the spring in hers also at some point.no snow to ride right now, so its not a big deal.all i can do is test on the pond.this is the worst year that i have ever seen in my entire life as far as snowfall is concerned.i have never had a year where i didnt allready have about 1,000 miles on by now.its sad!!!but on a better note, my sled is rippin up the pond!!!i still have a few choices of springs to try with my setup to get the correct rpm.if what i try today doesnt work, then im gonna get two more springs on the way to try.a psp, and a pgp.im sure that one of these will work for me, and one will work for the wifes sled.she has the 89a-10 weights with .83 in the heel, and 3.5 in the tip.it under reves with the ggg spring by 500 rpm,so im thinking that it will be close to 8500 with a pgp spring.im really starting to understand what works, and what doesnt from actually changing springs,rivets,and gearing, and logging everything down.once you start seeing a common factor with a change, its much easier to know what spring will do what.im hooked, and i wont stop untill i get all three sleds dialed in to a t!!!