450r spindles and front brake set up, plus they are aluminum. you will want +1 tie rods but its not an absolute must.
85-86 frame the 450r complete swing arm and rear end is a bolt on. again its aluminum so you basically have an 88-89 250r with less work. this does require that you have a hand file or dremel, the swingarm dog bone mount needs a TINY bit of adjustment. use the 2004-2005 450r arm, its basically 88-89 length.
cbr f2 f3 f4 front brake master cylenders, they are awsome, adjustable, more fluid, you should be using one of these anyway.
2-stroke dirt bike carbs, 125 cc bikes usually have 35 A/S carbs. 250cc bikes usually have 38 A/S carbs, certain years of like the KX500 had 39PWK carbs. also carbs off of some snowmobiles are the PWK series. a note, dirtbikes usually have short body carbs, either get a booted intake or a reed spacer to make up the difference for a trx install.
shocks are nearly universal, if you can get the valve and spring spec, the eye size and eye to eye length then your good to go. raptor 250 shocks on a blaster, 450R shocks on 250R, best thing to do is fire up ebay and pick a brand. try 'ohlins shocks' and look for ones that the lister did not list an application, then size them up for your project.
16 lbs radiator cap off of a 98 civic... i think. these is about double the stock coolant psi, so make sure your hoses and stuff are in good condition. this is promotes way better cooling.
yeesh, i think i just gave up all of my secrets.... well, not all of them.