The Cessna 337 had a slightly better single engine climb rate on the rear engine if I remember correctly.Start to sound doable, one thing! important to have an airfoil with low drag at CL 1.0 for better SE climb.
Did a check with 2x D-motor 88 HP FP prop, some 60 lb lighter. so 1600 as I was
SE climb @ 80 MPH 480 fpm (710 with CS prop non fethered)
300 fpm @ 3400´
100 fpm @ 9400´
The climb propeller we pick for 2 Engine drive, will become a bit more then a speed propeller with one Engine, the software calculate a climb, std, Cruise and a speed pitch prop, it is about 2" increase in pitch between each.
The real installed Power with the Revmaster might be higher then we calculated with here, but better be safe now then sorrovw later.
But for sure we give up a lot of performance in both ends of the speed spectra with FP props, in this case.