i thought there was no such thing as an xc 400. i thought he had an indy 400. I know there are indy 400sUmm.....pretty sure there is, umm because I have an Indy 400.... Okay so you have an Indy 400 XC. That was Polaris's early 90's "racing sled", BUT unfortunately I don't know a whole lot about it. If it is the 400 L/C engine it is SOLID!
The 1991 400XC's DID in fact come from the factory with a 440 in them even though it says 400 on the hood. They are pretty rare sleds. I personally would not go drilling extra holes in the tunnel to put an Extra 10 suspension in. That would detract from the value of the collector sled. Enjoy it they are great sleds.Well from what I can tell you DO have an indy xc 400 which DOES exist, but unfortunately you don't have the original motor in it. The xc 400s had a 396cc l/c twin. You probably have an engine out of a later year indy xc like a 93 or 94 indy xcr. On the upside it's still a solid sled.