most 450's have narrow frames for a conversion. if its your first conversion and its going to be for the dunes id think about a rappy or ds chassis, far easier to work with for 4 cyl swaps. ds has a beefy chassis from the get go and the rappies are taller than 450's. hybrid swaps can nickle and dime a guy to death. if you are really considering it, 2 things id like to mention that you spend good time on is sprocket alignment and chains and sprockets. there is a thread on the this forum atvhpjunkies.com that helps with counter shaft sprocket placement with swingarm length and angle. a good conversion with proper chain guides will have very little chain tension issues, another fix for this is a chain tensioner on a spring. also spend the money of chomo sprockets cuz replacing cases suck
'08 black- my whip: full RS-5, PC3, 400ex and HC intake=budget build. Walsh, fox, dwt, flexx, and goldspeed. KMS V2+ Vader special.
'06 white- GFs whip: Podium, Hiper Tech3 all-around, flexx bars, 474, and maxxis.
'07 trx250ex - daughter
'08 King Cobra - son '12 KTM 65 mod LL top 10 bike
MY WANT TO BUY LIST: 9" beadlocks with tires, Walsh link and white or black beaks. PM me if you have some of these parts