I didn't realize that we were discussing hot/high, 99% of my time is east of El Paso, in the flat lands, and that is what I was referring to, my apologies. I have some time in turbo-charged 337s, but I'm not familliar with the single engine service ceiling of those.
Its true that Cessna doesn't actively support the 337 series airplanes, they also don't support many other aircraft that they once manufactured, but that doesn't mean that those aircraft can't be maintained safely, or legally. Most replaceable items are off the shelf items from vendors. A lot of other model only specific items are easily fabricated, ie, sheetmetal parts, control cables, etc, but they aren't normally replaced in the course of normal maintenance activities. It would be impossible to convert a 337 from a military 335, the 335 was an unpressurized version of a 340.
Fxbat, the difference in single engine climb rates is that the rear engine is blowing clean air over that enormous horizontal stab/elevator, and the front engine is blowing against the frontal area of the fuselage. According to the 1L-2A-1 (USAF Flight Manual), in a single engine scenario, all external stores/ordinance is to be salvoed to drop the weight of the aircraft to 4400 lbs.
Sorry about the thread drift, but back to the original question, at Co-Ex, many motored time is many motored time, two throttles, two engines. No difference.
Dave