Proposed drivetrain...

[chicklin]

Ok, so after reading many threads and asking several dumb questions , I think I have settled on a new drivetrain setup:

SBC 350 -> NV4500 -> Divorced NP205 -> 4.56 gears -> 11.00 x 16 tires

I'm looking for a decent combination of off- and on-road performance. I don't need rock-crawling low-end and I don't need 80mph top-end. Just normal farm use and the occasional highway jaunt where I'd like to be able to do around 60 mph comfortably.

Couple questions:
- Anybody see an obvious problems with this setup? I'm pretty new to do something this in-depth.
- How expensive are 4.56 gears for the axles? Where do I get them? Can I install them myself? If it's too expensive, I can probably skip this part.
- Where will the fab work come in? I'm thinking motor mounts and mounts for the np205. That should be it, right? What about drive shafts?

I figure I can spend several months collecting parts. A quick perusal of eBay and craigslist suggests that I should be able to get the motor/tranny/t-case for less than $2k.

[k8icu]

That should be a good set up for what you want to do. The only thing I would recommend is to swap the axles with ones out of a K30 Chevy or CUCV. Or even a Mid 80s dodge with Dana 60s. This would give you the axle ratio you are looking for with out having to hunt for the ring and pinion to up grade the trucks axles.

[chicklin]

That should be a good set up for what you want to do. The only thing I would recommend is to swap the axles with ones out of a K30 Chevy or CUCV. Or even a Mid 80s dodge with Dana 60s. This would give you the axle ratio you are looking for with out having to hunt for the ring and pinion to up grade the trucks axles.

Think that'll be easier and/or cheaper? I have no idea what gears cost or how hard they are to put in the existing axles. I'm guessing that pair of axles is going to run somewhere around $1200, right?

Also, the truck I am getting will have a winch. Does the NV4500 have a PTO port or will I have to drive it off of the np205?

[chicklin]

That should be a good set up for what you want to do. The only thing I would recommend is to swap the axles with ones out of a K30 Chevy or CUCV. Or even a Mid 80s dodge with Dana 60s. This would give you the axle ratio you are looking for with out having to hunt for the ring and pinion to up grade the trucks axles.

Also, that sort of begs the question, why not just put the 715 body on a GM platform? If I swap out the entire drivetrain, including the axles, I am basically left with just the frame and sheet metal, right? So, maybe I just need to find an early 80's 1 ton Chevy and go the other direction.

Has anybody done this? How hard would it be to mount the cab on that platform?

[fisherman]

I would finish your build up first and keep the stock gearing in the stock axles. Drive it a bit and see how you like it. You can then change gearing after the fact. I figured I would need to re gear as well. No way now I'm keeping my stock gears, I love it. I can cruise 60 mph at 2900 rpms. I still have all the low gearing, which you will want with a sbc. Good luck.

[MarknessMonster]

SBC 350 -> NV4500 -> Divorced NP205 -> 4.56 gears -> 11.00 x 16 tires

I'm looking for a decent combination of off- and on-road performance. I don't need rock-crawling low-end and I don't need 80mph top-end. Just normal farm use and the occasional highway jaunt where I'd like to be able to do around 60 mph comfortably.

That's a good set-up, but skip the axle gear swap for later like fisherman noted above. I run SBC350 -> NV4500 -> D NP205 -> stock axle ratio -> 38.5" tire, and it is very well behaved on streets or trails.

If I were to alter the set-up, I would lower the gearing. Currently, I can run up and down the highway at 75-80 without rapping the RPM's. The low is low, but I can always find a use for "ultra-low". Based on your requirements, I think you'll be happy without the higher axle gearing.

[chicklin]

I would finish your build up first and keep the stock gearing in the stock axles. Drive it a bit and see how you like it. You can then change gearing after the fact. I figured I would need to re gear as well. No way now I'm keeping my stock gears, I love it. I can cruise 60 mph at 2900 rpms. I still have all the low gearing, which you will want with a sbc. Good luck.

I think that sounds like a good plan. If I can get 90% of the way there for $2k or so and it's good enough, why mess with it. 2900 for a couple hours should be no problem for the SBC and np205, right?

What tranny and t-case are you running? The NV4500 has the overdrive 5th, so maybe it wouldn't even be 2900.

[MarknessMonster]

The NV4500 has the overdrive 5th, so maybe it wouldn't even be 2900.

Not even close, but I don't remember how it runs out. The next time I drive it, I'll remember to check the speeds v RPM's for you if you're interested and no one else chimes in.

I'll be moving some stone with the aforementioned truck this weekend, so it'll make a trip on the highway into town.

[Barrman]

My 396/NV4500 with 11.00-16 Michelin XZL tires gets me 2000 rpm at 54 mph. Which is where I cruise at. Any faster and the brick of a grill and windshield drop the mileage exponentially. I get 12-13 mpg at 54 mph empty and 10-11 mpg loaded down with a trailer and another M715 on the back.

I have the stock gears with a rear locker added in. Stick with the stock gears. The money can be saved or spent on other stuff.

[chicklin]

2000 rpm at 54mph? Wow, that's nothing for the 350. How hard of a swap were those components? I assume you're running an np205, as well? Any pics of the fabbed parts? Thanks!