Gene, I have the 268 High Energy cam and kit in my baby and I really like it.  It's a good street cam and has a somewhat choppy idle.  Sounds good and runs good too.  Good choice.

Save yourself some money...instead of replacing the valve spings, go for some new valve springs... (sorry...I had to do it!)

Sounds like a good set-up, but what are you expecting to gain? The 268 cam is one of the best street cams around, and has been for years. But...unless you have an L82(9.0:1 compression ratio), you might be disappointed in the power gains. The L48 is an 8.5:1 comp. ratio. Bigger cams don't always make more power, or torque. The engine needs to have some mechanical compression to make good use of the cam profiles, and it's ability to fill/evacuate the cylinders. Just my opinion...just wanted to see if you were expecting a HUGE change in the engine characteristics with this swap.

I'd speak to the folks on their tech line. They may make a more advised recommendation, based on your compression. They measure a number of factors aside from lift, overlap and duration....

Just a little advice for when you get ready to "break the cam in."

Darrel is right on the money with his advice.