Did Carver ever use LH rotation engines for both Port & Starboard power, with the Starboard engine having a reverse rotation transmission?

New to us 1996 370 Voyager

I was pulling plugs and marking wires at both the cap and plugs on my starboard engine and noticed the firing order on the manifold is the same as my port engine 1,8,4,3,6,5,7,2.... Had to do a double take.... various other clues have me thinking the starboard engine may be a re-power, or at least pulled for a re-build at some point (Pulleys, Pumps, Pan, Block, Manifolds Valve Covers have been painted over with darker blue, the floor between the dinette seats appears to have been dissembled at some point). I would like to contact Carver with serial numbers but cant seem to find them. Where do I look?

TIA

Ken