I believe the multi-piston calipers are probably a better choice for "performance" reasons (meaning consistent braking) - they work well and wear evenly. But ...... when building a zillion cars and trucks, the floaters have got to be cheaper to build. Many decisions get made at the auto-makers, based on bucks. There is a Wilwood (public release) document you can (or used to be able to) access through their site - it is a PDF .....
ds719 that is "approved for external distribution". It has the critical mounting dimensions for all of their hubs, bearings, and seals which turned out to be pretty interesting data. If you can't find it - send me a PM with an email address.
The Shelby Mustang - TransAm Series, brakes for the racers - are big multi-piston Kelsey Hayes parts from a 60's Lincoln. They are massive calipers and mounted in the "forward" position. Initially,they could easily "out-brake" the Camaros and Javelins - I but believe the SCCA later let the others "catch up". Ford's answer to that little concession was to cast the "replacement" KH calipers in aluminum to cut the "unsprung weight". Probably a rare part these days....... the ones in this picture are either original iron parts - or cleverly painted......
The caliper brackets that mount the Lincoln brakes are like the Wilwood parts - notice the nifty "bump steer" adjustment spacer on the tie rod. I'm not so certain that forward mounting is the way to go on my '56 "Rally Car", there may be issues with the turning radius due to interference out front. The Wilwood caliper brackets have a double set of holes to facilitate use on the 3 bolt disc knuckle or the four bolt drum knuckle - either one. That makes me think they could come up with one to fit the caliper up at the rear............
Steve Metzger Tucson, Arizona