gpz 550 cams in a zr 550?

[Zaddict]

Has anybody done this swap? I have a line on a set of 1984 gpz550 cams. From what I understand, the zr550 already has the same cams as the earlier gpz's (the "first performance grind"). So it's a matter of whether the 1984 cams are big step up. Seems that way from the hp numbers - the '84 gpz 550 came with 68 hp (!) ...claimed anyway...

[Richard]

I haven't but THIS SITE might have some more info for you:

[Zaddict]

Well I went ahead and swapped in a set of zx550 cams (the cams in the gpz550 from 1984 on). The lift is the same as the zr cams but zx cams have something like 10 degrees more duration. Set the center lobe to 104 degree for both intake and exhaust. The gpz550 had the intake cam at 94 degrees. Haven't been able to test them out yet because I forgot to order a valve cover gasket (just ordered 3 - won't happen again!), but I'll report any difference I notice here. I'm not expecting much, the zr550 already had high performance cams, but hoping for a little something something.

[Zaddict]

lots of details about this swap and 550 cams in general in a thread on kzrider --

https://www.kzrider.com/forum/2-engine/ ... =40#775728

[Zaddict]

Just a quick update - I was initially underwhelmed by performance changes after the cam swap, but after dialing in my jetting all I can say is WOW!!!!! So much power, I'm constantly finding myself thinking "Uh oh, I'm going way too fast way too quickly." Sounds like a beast as well, with a loping idle that hints at pent up fury. Well worth the effort! You can read all the gory details in the thread I linked to earlier.