i've got a 1987 indy 400 engine (EC40PL-02) that needs a new crank. i need to know what year indy 500s will work in my engine. were all the 400 cranks the same? i've heard that they are all the same but no one can give me a straight answer. any help is appreciated.

yes they are the same

Indy 500 is really a big bore Indy 400 which is a big bore Indy Xcountry 340 LC

Even an Indy Trail crank would work I believe

Yes - the 400, 500, & Trail all use the same crank assembly.

Check out the Polaris website and search your model and year:

http://parts.polarisind.com/Assemblies.asp

Check the where-used/usage on the right side of the parts list and it will show you all applications where that (or any other) part number is used.

thanks guys.