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Throwing some first hand info into this conversation.. I've gathered solid info direct from Allison about our 3700SP (note not 3070) in the A1R trucks capable of 370 hp. Our units are rated for a sustained 935 lb-ft input and a 370 hp flash to the C7 gives a 928 lb-ft of torque at peak output. The key word above is sustained. The tech I've been working with on big brother transmissions (4500SP, 4700SP, etc) said our units are safe for the input as long as you use the recommend fluid (Transend of course) and keeping it cool. Longevity isn't an issue beyond that and eventual wiring issues due to age.
Caterpillar has commented on the 370 hp factory flash when I spoke to their power division. It's intended for non-highway use as is all of the engines ever put in an FMTV ever. Special contract, licensing, emissions, etc allows for this engine setup to be available for purchase should the military need for a variety of uses including for their arctic cats. The flash file I have has a note called "bearcat" which they didn't know about since they deal with pumps, generators, etc. The Cat library I have is recent and it only goes to 330 hp for the 3126B for our engine serials. Torque was around 865 lb-ft at peak for this engine. Overall you're getting about 63 lb-ft more torque and 40 more hp with a C7 if you max out factory settings.
I enjoyed my M1078A1R @ 370 hp as it would move quick and pull strong. I towed a M989A1 with 11,000 lbs of scrap for a total of about 54,000 lbs combined through some steep hills and she never skipped a beat. The stock 275 hp flash was a let down in comparison but understandably chosen for the quality of the driver and weight of the foot.
Caterpillar has commented on the 370 hp factory flash when I spoke to their power division. It's intended for non-highway use as is all of the engines ever put in an FMTV ever. Special contract, licensing, emissions, etc allows for this engine setup to be available for purchase should the military need for a variety of uses including for their arctic cats. The flash file I have has a note called "bearcat" which they didn't know about since they deal with pumps, generators, etc. The Cat library I have is recent and it only goes to 330 hp for the 3126B for our engine serials. Torque was around 865 lb-ft at peak for this engine. Overall you're getting about 63 lb-ft more torque and 40 more hp with a C7 if you max out factory settings.
I enjoyed my M1078A1R @ 370 hp as it would move quick and pull strong. I towed a M989A1 with 11,000 lbs of scrap for a total of about 54,000 lbs combined through some steep hills and she never skipped a beat. The stock 275 hp flash was a let down in comparison but understandably chosen for the quality of the driver and weight of the foot.