My PVC is going to explode

Or you can give me the water level in the well, pump model number, or horsepower and GPM, and I can tell you how much pressure it will build when you close a valve. And yes 1 1/4" pipe will have less velocity and should help reduce hammer.

At the time the well was drilled the static water level was 85'. That was in Sept of 2003. I installed a 1 1/2 HP Flotec Sub pump June of 2006. I found the model number of FP3242. At this point I am ready to try a CSV with a small pressure tank at the well head, and switch back to the 1 1/4 pipe to feed the tank. Could you please recommend a csv model # and a tank size for me.

I would use a CSV1Z or a CSV1W and a 4.4 gallon size tank. The Pside-Kick kit has the CSV1W, 4.4 gallon tank, pressure switch, gauge, PRV, hose bibb, and a manifold to screw it all together with.