I am working on my 1960 C10 and originally planned to swap a 6.0 iron block (L96) built for boost and backed with a Magnum 6 speed. Yes, boo, I suck. Even though the truck isn't original and I want to swap the 235 out, I still want to keep it true to its roots a bit with an inline 6, and I had considered Cummins, but want more budget friendly, less weighty options and have settled on a 292. I have a few questions about what to back it with for what I want to do with the truck. Its already been lowered in the rear 4", and the front is going down too, and although I still want to use it as a pickup, I am getting more ElCamino-esque feel to the whole thing then pickup. I love roadtrips and cruising the highway too, so I want an overdrive. My first idea was A833/NP440, but I want to hop the 292 up as well; EFI, cam, pistons...rods, turbo. The 18 spline A833 might hold up but its Dodge only bellhousing. What if I stuck with the Magnum? I have a 3.42 rear end though, and with a 0.50 6th gear, and 265/50r18 tires, I calculated 1600rpm at 80mph. That seems like a stretch, I can change the rear-end when I install the LSD, but I am really curious about this. My goal with the 6.0L was 2000rpm for 75mph (I think I did some math wrong on this though considering everything else equal). But say even 5th gear at 0.63, 2000rpm for 78mph. I mean, gas mileage should actually be decent keeping rpm low, the 292 makes power low down, could or should this combo work? Am I missing something important? If not, is there better transmission options, rear end ratio? Main thing I want is manual, with overdrive (shooting for 20mpg highway, but more is better), and shooting for a 292 that makes 300-400hp and 500-600 torque (no more then 15psi boost).
If you want to keep the rear that's in the truck now, which is probably a 3.90 ratio, then an overdrive with about .7 ratio would work well. If you have swapped it to a 3.42, then it might or might not be able to cruise up grades without having to get into boost in overdrive. Chevy put the 833 behind their V8 engines, which means you can put it behind a 292 six, since the back of the engine looks the same (aside from the 3 dowel flywheel on the later engines). You'll get crappy mileage, no matter what you do. Crappy means 12-15. But gas is cheap, so that shouldn't be too big of a deal. And you'll want to get out and stretch by the time you run the gas tank down, anyways. The engines were made to run all day long at 3000 rpm.
Best mileage will be with engine running at or near its peak torque speed. On a stock 292 that's 1600RPM.
To echo Squirrel, I have never known a person with a 292 get over 15 mpg. Just the nature of these engines
Like Squirrel said, GM used the A833OD in pickups for a few years, same gears but Chevy-friendly case. May be hard to find though. I'm installing one of the Mopar versions in a 56 Dodge flathead 6.
In my 63 I’ve got an S10 t5 with a hot rod works adapter to the factory bellhousing. Works great. Habitually procrastinating
Nope, someone swapped a 12 bolt with 3.73 gears from a 67-69 C10 at some point, and did so poorly. I put in a modern equivalent of the 14 bolt semifloat and that's what I want to stick with. (AAM 9.5", 12 bolt cover? Don't know RPO code, but it has 33 spline shafts, 9.5 ring, and will take some of the 14 bolt upgrades, shafts and carrier, I am told). Well maybe this will be a fun experiment? I guess if all else fails I can swap the motor and bellhousing out for something else and keep the Magnum. The 18 spline Dodge ones were put behind Hemis that made honest 400+ ft.lbs, but the 23 splines are weaker and Chevy didn't get the 18 spline version. There is a "hybrid" NP440 on eBay for $600 right now and a bellhousing for $200 I think. I guess the hybrid had Chevy bolt pattern on the passenger side, Dodge on the other and there are bellhousings drilled for both far as I gathered? They seem like a good option if I left the engine stock. I am trying very hard to avoid the T5 or World Class T5 because I hear torque is what kills them and I don't think a T5 would be long for this world with 500ft.lbs going through it.
About 15 PSi lol Actually I think PowerNation did a 292 and made 510ft.lbs on 10PSi. They had stock con rods though, I am planning to upgrade to the Molnar rods that are longer then stock so you can run a 250 piston, so I would be willing to put a bit more in then they did.
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