I seem to remember this problem coming up before, and it was solved by custom-fabricating stepped manifold clamps out of square steel stock, possibly key stock. It takes some creative grinding and drilling and/or a milling machine to fab the custom clamps.
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!