Is there any brownie box thats a single shaft that is pneumatic that would work for our application?
Yea there are some doozies out here in Colorado. One of the ones I think is really tough is I70 right outside Denver. If you are getting off C470 to I70 headed west you get dropped RIGHT at the start of that grade that goes for something like 15 miles. Its brutal. I've riden or driven some hopped up Cummins that even struggled (more EGT issues than anything) to make that pass without slowing way down.
I think the TRUE test of a good puller pickup is how it rebounds after loosing momentum. Most rigs with some power do great so long as no one cuts them off or they take a switchback and lose all their momentum. A truck with the right gearing and power can rebound after a momentum loss, not leaving the driver cussing like a drunken sailor when someone cuts them off on a long grade when they are loaded down
That's no joke, Eisenhower and grades like that gets everyone crawling. You're quite right. It doesn't matter how much power folks have on hills like that about a third of the way up, heat is the great equilizer and everyone who is loaded down hard is all crawling at about 20-35mph. You are quite right about recovery I noticed a few times some of those new fancy trucks barreling past me near the bottom of some grades where it was fairly straight but when they had to nail the brakes for the curves, they were darn near dead in the water and I was right up on their tail in no time having to back out of it and wait on them while they billowed black smoke and went nowhere It's obvious youve spent a LOT of time driving around in those mountains
YEs there are some single countershaft brownies that are air shift, but finding one is near impossible. I looked for over a year to try and find one because I wanted one so my wife would be able to drive it easier . The RP 8000 series is air shift for sure they are 4 speed air shift brownies. any of them with P in the number designation are air shift ( P for pneumatic shift ) but the 1241p is a twin countershaft ( got to remember the only one that has been built in the last 40 years is the 1241p. With the demand down and scrap prices high in the last few years the ones that were laying around got turned into toyotas, there's only a few wrecking yards in places like Oregon and Michigan where they have a history of heavy hauling where the things still regularly pop up)
Of course, you could always go nuts and ditch the adapter ring on teh back of teh engine and use an sae bellhousing and pop a spicer p-8500 16 speed combination box on there that is basically a 4 speed with a 4 speed air shift brownie attached directly to it . THey had this really nice 4 notched air shift handle. They actually had a 4x4 and a 5x4 version of this , it was also known as an SST at one time