does anyone know if the 300 front diff lock procedure is the same for the 500 as the 300 my 500's diff looks the same as the 300

 

Nope- totally different guts between the two. The only way to get a locking front end would be to put a new style one in there. For the amount of time and cost your better off to buy a new wheeler if you really want a locker.

 

I have an 01 250 and it has the front posi all that was required was to add 1 inch to the length of the control rod.