Lower priced Power lok, sure grip units on Ebay.
I wouldn't sell you my 60yearold one for that ............
IMO
The clutch type is great for racing.
IMO
the clutch type is less than great for a streeter, unless you tune it, which can take several attempts.
IMO
The cone types however, can be set up on the bench, bolted in, and done.
And to a degree, fine-tuned with whale-oil additive.