Just FYI, the FMF pretty much sucks on the 87+ LT's, for both the 250 and 500.
However, they did do a good job with the 85-86, so don't eliminate the FMF just yet!
If he's willing to do a custom pipe for you, make sure it's superior in comparison to the FMF and tell him that we can help market it here.
Lots of guys still riding the 85-86's that feel completely left out in the pipe dept.