Unless I'm missing something, I believe you can just slip your 71 legs into your earlier yokes. That's what I'm planing to do on my 66. Didn't use a micrometer or anything high tech, but the width looks the same with my tape measure. Tubes are the same diameter. Don
I don't think that would work w/o mods, the pre OIF fork tubes have a taper at the top to snug into the top tripleclamp, while the OIF fork tubes are not tapered and held in place by a clamping action.
Will S. BSAs: '66 & '69 Lightning Triumphs: '68 TR6R, '68 Bonneville, '73 TR7, '55 6T '71 Norton Commando
Will/pod It depends on the year of the OIF forks as to the top taper/ or clamp. The 71/72 had the taper, later ones like the T140 with a disc had the pinch bolts in the upper clamp. I plan on useing the stock tubes/lowers/wheel from my 71 Rocket 3 on a 66 Spitfire and everything measures out the same. As the R3 is getting a T140 disc front, I've looked all these pieces over pretty closely (yes I have the correct T150 lower yolk). The later disc fronts were held differently at the top and the spread was wider. Before anyone jumps, yes I'll have to use twin springs and dampers in the Spitfire as these differ from the triple parts. Don