I have done something like that, but i figure if your going through the work you might as well go big right. I have taken my blaster and fabed it up. starting with the engine i tore out the 465It engine sitting in my back yard. sits the same way as the yz and the stock blaster motor(infact it took no mods to fit into the back trailer arm bolt set up) only thing it took was some time to fab up the mounts. used a couple pieces of 1/4 inch steel to make me the mounts. however the engine had so much power on them the motor ripped the entire tops of the mounts leaving a very loose motor(when they broke it broke my silencer tip at the factory weld) the main header pipe was the tricky part. i used part blaster exhaust part 465it exhaust. had to splice them together and fit it in. air box needed some extra attention being the fact the stock air box just needs to use a bit of heat/water tight silicone to seal the new air hose into the air box. my bike has more power than i could ever immagine having and belive me it will rape your 660 raptor in a heartbeat.. had to change stock front sprocket to get more torque. since i kill raptors all day i figured id mess with people and put me some raptor plasitcs on my beast.
since i originally started this build i have not had a test ride or even a ride without loosing parts. this 465it engine rattles alot and will shake you off the bike with its sheer power. i am now using stronger thicker metal for my mounts and just for precaution i bolted a piece of chain around the frame and use it as extra strength to hold this beast down.