The damper I made up as a test project is currently being fitted to a very nicely restored 235 which hasn't gotten to the starting and running stage quite yet. It required shortening the balancer hub about 5/16" to get the belts to align properly, and a corresponding amount needed to be machined where the hub OD meets the main body for clearance at the timing cover seal. I've also come up with a 3/8-16 shouldered Allen bolt that will replace the tapered-head screws for attaching the pulley to the balancer and help align it properly. I'm planning to possibly build another one and do some further testing which would also provide me with an incentive to get my GoPower engine dyno back in operation!
Jerry

Edit: On the pulley diameters- - - -some of the later 235 dampers had a much larger-diameter belt groove, so I don't think the big block V8 pulley will be a problem. That's particularly true if an alternator is used. Overspeeding a generator can throw windings out of the armature. Altertnator rotors spin several times crankshaft speed with no problems at all.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!