Blue
Block front is the old style or Old Skool front end from Assocaited. Not the new style reactive caster front end. (on your 3.1)
Old Skool as it is called is $20.00 complete, has no adjustments for caster and camber built in to it. I think it comes pre set with -2 caster and -1.5 camber. It can be adjusted with shims on the bottom where it mounts to the car. Tapered shims were available, but i don't know if they still are. This front end would be more consistant. Maybe less agressive.
David L please correct me if I am wrong.