you should be fine, oem parts are usually better for these bikes. just make sure to have it welded.

Why weld it?  The majority of the LT 500 cranks are really tight and do not need welding.  Welding cranks became popular and necessity when everyone started building stroker cranks.  Stroker cranks cannot usually have the same interference fit as stock cranks without splitting the crank pin hole because there is less material between the crank pin hole and the outside of the crank.   

We rebuild a lot of cranks that were previously welded and it adds a lot of unnecessary cost to the rebuild.   Many times a rebuild on a previously welded crank is substandard because the crank pin hole is often damaged and distorted from the previous welding.

We only weld cranks that have a loose interference fit or if the customer insist that they want it welded.