Reply to "Big bearing front spindles?"

Finally answering Doug's question I missed from several pgs back-
"Bosswrench, Do you know what calipers were used with the 1.25 front rotors at LeMans?"

On the GR-4s, they originally used gigantic iron three-piston calipers similar to what was on the GT5 and GT5-S cars 10 years later. The smaller rear 3-piston brakes were sourced from Rolls-Royce, altered a bit for slightly larger rotors in back. GR-3 Club-racers also used iron 3-piston Girlings on all 4 corners, with the later pair-of-pliers e-brake system. These Girlings are incredibly heavy: when I mounted up a genuine GR-3 brake system on a '72 Pantera Judy & I were racing decades ago, I had to use both hands to hold one caliper!
ALL the race cars used 15" wheels and are still required to today by the vintage rules. So the 1.25" thick 'race' rotors are virtually the same OD as our 0.81" thick steet rotors and thus have the same mechanical leverage. Far as I remember, failing front bearings on gr-3s & GR-4s were not the problem; breaking stock rear axles after 3-4 hrs of track running was (and still is today)!

On spindles: early pushbuttons used a different casting in which the spindle was removeable; the spindle had a taper held in by a big nut on the backside. I suppose if one had such an upright, you could have a replacement spindle made of better steel & with bigger bearings. Not a direct swap: the early uprights used integral steering arms while all later front uprights use removeable steering arms & integral spindles. Dunno what front bearings were used on the earlies. But as Steve W said, that spindle is no longer generally available except as recycled parts from junkers. Early car's mating a-arms were different (wider), too.