
J/K...lol
A cam can be custom-designed By Delta Cams to match whatever you want it to accomplish for your engine. There are a lot of variables involved in choosing exactly what lift and what duration will work for your needs. I'll just leave that to them - they are the experts. So if you wanna know about Cams, I'd highly recommend you giving them a call (use their toll-free number if necessary), and talk to them. They are nice folks and I'm sure they will have no problem answering any/all questions you might have.
As for puting a new cam in a used head - you should have a manual around handy so that you can make sure that your head, rocker arm assembly, etc. is still in decent enough shape to install the cam into it. I personally always check the spec's, inspect everything for allowable tolerances, and visually inspect everything else before I install a new cam. Also, I always use plenty of good quality cam assembly/installation lube, and re-adjust my valve clearances before I start my engine up. Then I turn my idle up high and let the truck run for about 20 minutes or so to break in the cam. Then after a few days of light driving, I check my valve clearances again, adjust them again if necessary, and change my oil and filter.
As for the pin that aligns the cam with the gear - I've seen first hand what happens when the pin snaps or comes out and the cam stops spinning while the engine is still running, and it aint pretty. Unless of course you really enjoy looking at holes in piston tops, and all-bent-to-hell valves....lol
So obviously you want the pin in there snugly, and you want to make damn sure you tighten the gear down on the end of the cam to the proper torque specs. The manual explains that all in detail, and the guys at Delta Cam will install a freh pin in your new cam and make sure it is in their snug. So if you get a cam done by them, I personally wouldn't worry too much about it.
So far, I've never had one fail or had any other problems with one yet. And Idoubt if lasthas much to dowith that. If I was lucky, would I have been born this ugly and poor?