yz400 motor in an R

[quadracer34]

I got a full 1999 yz400f dirt bike in good condtion for the right price and was thinking of sticking the motor in my 87 R. The R runs great but i like working on stuff. Right now it's got about 20hrs on a Pro Cross jug and head with a CT port job, Pro-x piston and hot rods cranke, runs 210 comp. +2 a-arms W\ Works shocks up front and an LSR axle, swinger, and carrier. alonge with lots of good extras. So is it worth all the work? And how much fab. work will this take? Any tip, tricks or even pictures would help. esp. in the swingarm area.
Thanks Ryan

[mikeminyard]

Don't ruin a good frame. Your R should have more power anyway. Keep the bike for riding when you feel like riding something different.

[quadracer34]

dose any body ealse have one and like it. even with maybe a 426 or something?