need new clutch

Here's my advice go to AutoZone and buy their heavy duty stock replacement diaphragm clutch.
It took two years of heavy abuse with slicks at the racetrack to finally make it start slipping in 4th gear. Spend your money the way you want to but it doesn't sound like you need anything more than just a regular heavy duty stock clutch. And don't go to the dealership and pay twice as much for the same thing you'll get at Autozone.
I should have been more descriptive in my original post. My 70 Swinger 340 is 95% original or OEM. I don't care about 1/4 mile passes or tire melting light to light performance. What I do want is a smooth operating OEM style clutch kit that will hold up to some spirited driving and the occasional burn out. Any takers out there?
Jerry