Cam?

Depending on the specs they probably have variations of lobe profiles that they use on the XR650R cams(that you can get now if you want).

I Have talked to Hotcams multiple times the past 2 months and it will be late Feb or mid March.

I was looking at the pics of the two cams and it looks like the 650 has a realy long duration

That's what I would be afraid of.

Since the two machines share similar motors but different chassis I would be leery of it. In my mind it's like a truck cam for a SBC and a "corvette" cam for a SBC. Sure they share the same parts but the two engines are serving different purposes. (yes I understand that the XR650 head and block are essentially the same but you get my point...one has to haul a LOT more weight.)

The 650 cam pictured is a Stage I Hot Cam so that why it looks bigger because it is. Lobe lift on the XX cam is .255/.259 and the lobe lift of the stage I is .307/.307
Smo0oth is gonna have a 11:1 CP, this stage I cam and my XXR ported head so we will see when he dynoes it, he said hes gonna have a stocker dynoed to compare the two on the same dyno.

Its also kinda like the YFZ guys, the YZF cam specs and the YFZ cam specs are basicly the same just the exhaust cam timing. The YFZ guys change the timing on that cam to the YZF spec and gain cheap power.

There should'nt be any and critical negative effects since both motors operate in the same RPM range and is only larger by a few cubes. If the XX only had a longer stroke or only a larger bore making the cube difference this could cause some problems. I believe the XX cam will just be a tweaked XR cam to benifit use of the FI