I was looking at some cams the other day, and not only the prices were surprising me, but also that I would need some other stuff...(..drivetrain upgrade).
Is there an cam ..(and cam gear), that is reliable, powerful that does not require me to change other stuff in the engine or transmission?
I've seen stuff saying "stage 2" and "stage 3".... but they all require other stuff, I guess other than that... it would be blowing the engine.
Thanks!

 

The only camshaft type that could concievably installed without requiring all manor of upgrades would be a cam designed to improve torque caracteristics. The 1st, 2nd and 3rd stage cams that you were looking at more than likely had grinds ment to develope increased power in the upper rpm ranges; and yes, additional improvements would be required to maximize the effect.
Unfortunately, there is no "free lunch" in the motorhead business (unless you subscribe to "turbo widgets and such) and any improvements to bottom end torque is usually at the expense of high rpm operation (as relateing to cam grinds).
If you're really interested in following up on this you might give a call to some of the cam grinders who advertise both here and elseware (Like Crane Cams, Crower, Iskanderian, and others and ask their recommendations.

P

 

When a cam is altered so much from stock, the factory valvetrain works overtime and is unable to perform as the stock one, and that is when it needs to be upgraded. If you have a mild street cam grind, it shouldnt be a problem.

 

With regards to cam lobe lift, yes; because with radical increases in lift it usually requires Titanium retainers, special spring sets, hardened valve keepers ect. And then there's the improvements needed both upstream (intake) and downstream (exhaust) which are needed to optimize the engines' better ability to breath.
Torque(r) type cam grinds traditionally don't require radical inprovements to the valve train (although most do anyway) since the modification to the lobe profile is to the ramp, duration and overlap specs areas. The base radius and gross lift remain the same, thus are easier on the rest of the valve train.
Honda developed a novel approach to this problem by developing the Vtec, in effect a dual-personallity cam grind(s). Thru a unique use of hydralics, the system switches from a mild cam grind at low rpms (for drivability) and then to a grind more condusive to high(er) rpm use - all automatically. 'Cool!!