I bought the McLeod SSpro for the '69 post L78 which has a 427 now. It may never see the strip.
I cut my teeth regarding clutches with a 3200lb '55 chev with this very engine. Started with a DF and a Muncie, that slipped and warped the steel flywheel. That's a tough pill to swallow beings how much those flywheels cost. I went with a steel 40lb flywheel, and a full ceramic disc and that same pressure plate, just rebuilt. That slipped so eventually went to a full metallic and switched to a jerico.
All these saw a lot of street miles but still saw some very high rpm launches, wheels just barely separating from the pavement.
Now that car's gone but upon teardown, noticed the flywheel showed signs of heat so had it surfaced.
That DF pressure plate had seen better days so it got tossed in favor of the Mcleod, which is the same pressure and again, the same disc as the centerforce.
IIRC, our engines are very similar except I'm running some worked 063 heads and a SFT Crower 01351 cam.
I'm telling you all this because so many things are at play here. Whichever clutch you pick, it'll be a compromise. Go too light, you'll slip, just won't know the extent of the damage till it glazes or lets go, but it'll always slip a little. Slipping will heat your flywheel/PP and the more aggressive of friction composite, the less it'll slip but the more that disc will cut into your steel surfaces. The safest way I know to run the street and strip is use a Mcleod RST, save the RXT for above 600ft lbs and higher rpm launces.
Spend the money now or you'll for sure be changing out your stuff within 2 to 3000 miles. That's IF you dragrace a little.

Well, I finally bought a clutch disc. This really had my head spinning as I have a car that is truly street driven that sees the track a couple times a year. My initial feeling was to get a dual disc clutch but I want a car that my peanut of a wife can drive too.

So I went with, what I think, is a well designed disc made by RAM. The part number is 310M. Here is the description:

Ram 300 Series clutch discs feature a polyurethane-encapsulated sprung hub to handle higher shock loading than standard discs. They also have premium, non-asbestos, organic facings bonded to a steel backing for better heat dissipation and greater strength. Available with a marcel carrier (300M Series) for reduced chatter and smooth engagement, they work great for race or Hot Street applications.

It has 8 springs in the hub where most have only 4-6.

I plan on installing it in the next few weeks and will give a full update.

Thanks to everyone for all your input.

Kurt

Just saw this, I installed a Ram Powergrip HD (900 series) in my 440 six pack 'cuda and love it. It is very streetable, makes a hint of noise when cold, but drives just like a stock clutch. We just installed the same setup in a friends Challenger with 426 hemi, but won't have that out for testing for another few weeks. Both cars will see dragstrip duty at the Pure Stocks along with street driving, so we will see how they fare.

I talked to three different respected driveline/clutch/hot rod shops before purchasing and every one of them recommended Ram without hesitation. Will be curious to hear how the 300 series works for you.

I continued this discussion on my thread......

https://www.yenko.net/forum/showthre...26#post1417726

Kurt