Any one know how much increse in hp I would get if I put some se 536 cams in my 2000 X1 0r my 2000 m2 engine with out head work?

If no one here knows/answers, you might be better off asking this question on www.badweatherbikers.com.

The additional lift will do nothing for you as stock Thunderstorms nose over on the flowbench before .500 lift.

The timing is broader and the intake close point is later, which is better for higher rpm. But you may lose something down low at stock compression. The additional overlap will make them more sensitive to the exhaust. With a good exhaust system, that's a good thing; with a bad system, the cams could actually take you backwards.

Watch the exhaust valve to piston clearance, those cams have a large TDC lift figure that often causes interference with the little valve pockets on stock pistons.

Also, you'll need some better valve springs and possibly some additional retainer to guide clearance. I've seen those cam have issues with rocker arm to cover clearance and tappet anti-rotation pin clearance as well. Check it all. They're not bolt-ins by any means.

Thanx for the info. I wanted to know if it was worth doing before I go with the 88" or 90".

Aswracing: Are you stage 2 thunderstorm equivilent to your stage 2 Xb heads for performance.

hang on a sec..................

there's a HUGE difference in the question as it pertains to a 1200 as opposed to an 88" or 90" motor!!!!!!!!!!

What EXACTLY are you trying to achive?????

A cylinder head can only flow so much air. So do both heads flow the same or is one beter than the other?