I'm going to try to make this as breif as possible.
I deal with Comp Cams and I know a technician at Comp Cams that would help you - his name is Darren Miles.
But your problem is - you want your cake and eat it too.
The problem with camshaft design is that when you get one thing, you have to be willing to give up something else. Without knowing the year and model of Vortec engine you are using, which head, and what you plan on putting it in, it is hard to just generalize everything into one simple little package.
Let's start with the basic's.
A camshaft has a couple of basic parts, you have the ramp - which takes the valve from a fully closed position and moves it to fully open. How fast this is done is determined by which type of lifter you use and how much ramp speed the lifter, valve spring and valve can take.
Valves are opened and closed by a spring. Usually one or two springs and a dampner. The purpose of the dampner is to absorb some of the shock and keep the valve from fluttering.
When the camshaft goes to the top most position, when the valve is fully open, the spring pressure on the top of the valve is commonly refered to as " Over The Nose".
The more lift you use, the faster you open the valve and the faster you close the valve, the more spring pressure you need. The more pressure you exert on the stem of the valve, the better the valve you need.
If you use a solid lifter, flat tappet camshaft, you are limited to how much ramp speed you can use. You have to keep it slow or you will tear up the camshaft and the bottom of the lifter in short order.
The goal in a race engine is to open it as fast as possible, keep it open as long as possible and shut it as quickly as possible. The length of time that you keep the valve open is called your duration.
High lift, long duration camshafts do not produce much horsepower.
What we are looking for is a happy medium, where we get good lift, good duration and a long life, because you are not racing at Daytona, where you run 500 miles and then throw it all away.
What I would suggest is that you find yourself a good engine shop where you can either get them to take your heads off for you and inspect them and remachine them to accept a better valve and spring. Or if you feel confident - you can take them off and take them to a machine shop and have them machine the heads and do a 3 way valve job with better valves and assemble them with the valve spring of your choice.
The valve spring, needs to match the camshaft. As will the timing chain and the gear on the bottom of the distributer or oil pump drive. With a roller camshaft, we usually go with a Bronze distributer gear.
While you are at it, you might want to look at getting screw in studs and guide plates mounted to your heads and a better set of push rods.
I would limit the amount of lift to about .480 if you wish to have any torque in the lower ranges and still be drivable around town.
There are good Vortec heads and not so good Vortec heads. If the heads were made in Mexico or were the pick up truck - low compression, small port size heads, you would be better off to invest in a better set of heads or aluminum heads. Either way - it is going to be a very large investment and not just a simple camshaft swap like it was 25 years ago.
