These are all great replies. If the stock clutch plates are just as good or better than the Barnett plates, and the Barnett spring kit is is better. Which I am thinking to be true, since in the automotive world diaphragm clutches are not as strong generally as individual spring clutches. I am going to purchase the Barnett spring kit along with the stock clutch plates.
Even the the Warrior world, this option is what is recommended. That is if you are talking about buying the Barnett "Spring Conversion Kit" which includes the pressure plate and two sets of springs. Barnett also sells the coil springs only which will only work on a Barnett pressure plate.
I also assume in your bolded statement above you mean stock (friction and steel) clutch plates.
Let's list whats available:
Spring Conversion Kit includes pressure plate, 6 lite coil springs, 6 heavy coil springs.
Springs only, coil springs and must be used on an existing Barnett pressure plate.
Clutch packs that include the friction and steel clutch plates.
Stock diaphram spring, must be used on stock pressure plate
Stock pressure plate
Stock friction and steel clutch plates
The optimum set up as noted by Brent is Barnett Spring Conversion Kit along with the OEM stock friction and steel clutch plates.
Next best set up is stock friction and steel clutch plates with stock pressure plate and double stock diaphram springs.
Springs are not interchangable between the Barnett and OEM pressure plates.
Like RaiderRick said, the friction and steel plates need to be inspected and measured to determine if they are worn out. And fluid level needs to be checked.
Rczap, let us know the best price you find for the Barnett spring conversion kit. I'll let you know what I have listed on my home computer.