If you know then please help me, I am desperate.

any one you want? depends how much work you wanna do

470,521,537,617,670 back in the years of the PRS CHASSIE........THEY WILL ALL BOLT RIGHT IN.....JUST HAVE TO PLAY WITH WIRING A LITTLE.........OTHER THAN THAT FIND ONE OF THOSE.................IF NOT YOUR INTO DRILLING OUT PLATES AND HOPEING THINGS FIT

1995 and up 670's will only fit if you tap the bottom engine mounting holes, these were used to bolt into the engine plate for the s,f 2000 chassis. 94 and down (prs like you have) have 4 seperate mounts that are bolted to the sides, by the carbs and exhaust.