Doubt it. Take it from me, who learned the hard way...take the Jag as it is. A reliable, efficient trail sled. Clean up the clutches, clean up the carbs, make sure the belt is good. Are you looking for more power or sound?
I put one on my sons 97 jag .I had a aftermarket silencer laying around from one of my zrt's that had 3 individual silencers. I cut 1 of them them from the group of 3(the side that had the mounting hole on it) and made my own bracket bracket out of lite metal and bolted it on. The height of the zrt silencer was the same as the jag muffler and the pipe and gasket fit right in with no troubles.It sounds almost stock at idle and when you get on it has that 2 stroke crackle to it.We ran this last year with no problems,I just added a 2001 zl rear skid and a-arms and front shocks,tach,twin 35mm flat side carbs with air box removed and k&n filters,and removed the oil injection system in favor of pre mixing.
The 97-99 jags had the same body style. I just sold what was left of the zrt silencer on ebay last week.I could have cut one of the pieces off and gave it to you for the cost of shipping.The brackets are easy,1 L bracket on the bottom and 1 straight bracket for the top,I did it with a hacksaw and a drill.97-99 have same body the 99 has the turned up tunnel in the back,97 and 98 have the straight tunnel.I can e-mail you a picture to show how simple it is to do.