The pipes produced the most hp at high rpms, upwards of 9000 and the motors just couldn't continually rev that high. Sure you gained 25 horses but never knew if the motor was going to last. And yes, there are guys that have SLP pipes on the XLT for the last 10 years,have over 10 000 miles and maybe rebuilt the top end once on the weekend. The 580 was a better engine than the 597's though. Around 97' was the worst years... I had a 95 that gave me troubles with the crank. 3rd bearing in on the PTO went. Anywayyy hopefully you did the mods to the crank case for the oil jounal while you had everything split..
If I was to build one of these (and I'm still thinking on it 95 XCR with the XLT engine that my neighbor has) I would split the crank, drill the PTO oil journal the same size or a tad bigger, get a 4 line pump from a liberty and tap the 4th line directly over the PTO bearings. Then I'd slam the SLP pipes on. Atleast then you know the PTO bearings should be good to go...You'd have a sled with lots of hp and the nice sound of the tripple. And maybe even a reliable one!
540 Open Mod
1995 Polaris Indy 500
White EPI primary spring with 10 weights
Purple EPI secondary spring, 45/36 HRP helix