M35A3 power and speeds mods?

[Lar45]

Hi everybody, Sorry, lots of questions.
I used to be on here many years ago, but the wife talked me out of buying a Deuce
Now I see an A3 for sale just 2 miles from my house! It looks fantastic, but I'm still trying to convince the wife that I NEED one.
Anyway, The big part for me would be the power and increased speed modifications that would be needed to make it a daily driver. Possibly bobbing into a 4x4?
For power increase on the Cat 3116, I found some videos showing how to adjust the fuel limit on the Rack. Looks pretty straight forward.

Next, I found a video shows adjustmets to the Governor to reduce the turbo lag and get more fuel when you step on the peddle.

Now on to gearing/overdrives:
On The A3 I'm looking at, the guy says the Allison transmission already had the overdrive gears installed.
I read a bunch on the 5 ton transfer cases with some of them having an overdrive built into the high range. I don't remember when #, maybe the M939???
Has anyone done the 5 ton transfer case swap on deuce to get more highway speed?
My reading also turned up that there wasn't a very high opinion on this 5 ton transfer case, saying that it was questionable for heavy offroad use. Any truth to this, or is it just one guys opinion?

What about doing the 7 speed Allison transmission swap? It's supposed to have 2 overdrive gears
How hard is this to do? Will it fit with the transfer case in the stock position?

thanks in advance.
Glenn.

 

[Hummer Guy]

The A3 Allison doesn't have a overdrive, from what I heard they cruise at 45-50mph. The A2 deuce has a 5 speed :85 overdrive transmission. They cruise at 45-48mph as well, but you can go with a bigger tire size to up the cruising speed to 55-58mph. I have the 395 46in tires on my A2 and it would do 60mph but I prefer to cruise at 55-58.

For a daily, I think you actually have to drive one to consider it, personally, I'm fine with the power, but it would be nice to have a little more. The biggest power upgrade you can do is swap the turbo out, one guy on youtube done that with the M35 multifuel and claim its way more powerful and able to run higher boost with lower EGTs. He swapped the hx40 turbo on it

 

[glcaines]

I have an M35A3 W/W and I love it. However, this truck is not a daily driver. I'm not sure why you would want it to be a daily driver. You are going to have poor mileage, tire wear and put a lot of mileage on the truck which means maintenance issues.

 

[Hummer Guy]

I have an M35A3 W/W and I love it. However, this truck is not a daily driver. I'm not sure why you would want it to be a daily driver. You are going to have poor mileage, tire wear and put a lot of mileage on the truck which means maintenance issues.

Its not too bad for a daily depending on where you use it and how big the parking/streets are in your city and the tire wear isn't too bad depending on which tires you go with either. Personally, if I was to get one to specifically daily I would inspect everything on the truck thoroughly before purchasing it , I would save some money on the side for upgrades such as sound deadening, A/C, weather stripping, and other parts etc.

I have the A2 version and have done a lot of upgrades to make the truck more comfortable and daily worthy.

 

[Adrok]

Dunno about power or speed, it IS a M35 after all.
For casual and daily, I put a LOT of focus on brakes, fuel, and low-maintenance changes first:
Wheel cylinders, running vents to air box ( eliminating highway draft tube ), cleaning / maintaining fuel system and injector pump.

Made the truck MUCH more comfortable and intuitive to drive. A well maintained fuel system definitely helps with throttle response.

Cheers

 

[Jeepsinker]

Power is a bit irrelevant here since your top speed is limited by the final output ratio of the transmission. You can have 600 hp but you'll just get to 45mph faster..
You can install some taller tires ( 395s) to push up maybe to 50, but after that you need to either look into a transmission swap or alternate axle gearing. 5.13 gear sets are available from Ouverson engineering, but they're quite expensive. That would get you to a comfortable highway speed. You could consider swapping in an Allison 2000 and honestly the price would be comparable to the gear swap. That'd be a much more realistic swap than the 7 speed too.

 

[Hummer Guy]

Power is a bit irrelevant here since your top speed is limited by the final output ratio of the transmission. You can have 600 hp but you'll just get to 45mph faster..
You can install some taller tires ( 395s) to push up maybe to 50, but after that you need to either look into a transmission swap or alternate axle gearing. 5.13 gear sets are available from Ouverson engineering, but they're quite expensive. That would get you to a comfortable highway speed. You could consider swapping in an Allison 2000 and honestly the price would be comparable to the gear swap. That'd be a much more realistic swap than the 7 speed too.

Only thing with the Allison 2000 is the transfer case would most likely have to be moved back and the driveshafts would have to be modified for it, but it would definitely be a better way to go then the 5.13 gearing since your acceleration won't be affected, with the 395s I'm able to do 57 at around 2200 RPMs, I don't like holding the engine over 2200 RPMs for long so I just settle with it, but I would love to have my truck at 62-65 at 2,000-2,200 RPMs so I can keep up with governed trucks on the highway at least.