The 5 1/2 clutch as shown also has a flywheel.
This would NOT be for street being the flywheel is only 7 lbs so getting the car rolling from a stop would put too much heat into the clutch.

It would though and it's purpose if for racing where we use high RPMs to get car rolling but after that due to the total low mass weight would spool RPMs up or down very quickly !

For street the 8 inch would be the way to go and you would have to get a flywheel and release bearing for it. You could check on Ebay for I see a lot of Tilton parts there.
This 8 inch with 3 discs and floaters will take a ton of horsepower with no slip.

No race designed parts are not cheap. Tilton clutches are $600 plus but really single disc clutches are not that much cheaper.
I'd sell the 8 incher for $400 plus shipping cost.
It was never used so it has been sitting in garage since I got it back in 1997.
Later on you always can change the makeup of discs for Tilton sells carbon, metal, etc types .