Planning on doing a cummins swap in my old hi-boy *gasp I know* and planning on using a zf-5speed but was wondering if anyone could tell me if there was a difference between gas/diesel 5-speeds throughout the years and what t-case was used by ford. Would be a manual shift setup of course. Thanks for any help.

 

First of all I think that is going to be a very cool truck! I would like to do either a PSD or cummins in a similair truck. Secondly I do know that the gas ZF's are not as strong as the diesel ones. And the older zf's aren't as strong as the newer ones. So I would get a ZF-5 from a 95-97 PSD truck as well as the transfer case. Or since you are already going to be custom a ZF-6 and a manual t-case would be cool too. I know the older ZF's are rated at 420 ft lbs and the newer (95-97 era) are rated at 450 I think. ZF-6's are rated at even more.

 

Your best option is to use an NV4500 and NV5600. The new G56 transmissions are also pretty decent.

The ZF47 is not a very strong transmission compared to the NV4500. Those that have done the swap with the ZF with moderately powered engines have had problems with these transmissions in the long term. Beefy PSD's seem to have less of an issue, but I still bet problems will develop long term.

The NV4500's also seem to shift better, and once the 5th gear problem is fixed, are an excellent transmission. Have you priced the kit to adapt the ZF transmission to a cummins? For a couple hundred more, you can have a fresh rebuilt NV4500 with 5th gear fixed. It bolts right up to the engine as it was made to, you don't have to worry about clutch/flywheel clearance issues, the original cummins starter works (no custom starters like some adapter plates require).

All in all the issues associated with using the ZF transmission are nonexistant when using the NV4500 and you get a better transmission to boot. The ultimate solution would be using a NV5600 and have one 6 speed beast. This is the option I was going to take.

I would really take a look into getting an NV4500/5600 instead of using the ZF transmission. My research has shown that it is really worth the cost.

 

I have seriously thought about that, easier and cheaper but My experience with anything NV hasn't been pleasant. There are guys around here that are making them survive alright. I really want to do a automatic but the price of a built auto scares me at this point. What t-case does the zf-5 use?

 

The key is that they are making them survive behind PSD's. The cummins is a different animal. For a stock or nearly stock engine, you won't have an issue. Once you start getting around 500hp, things begin to change.

For automatics, I would look straight into an allison conversion. It will cost more, but you will have the undisputed king of light duty automatics on the market.

 

No, making them survive behind cummins conversions. Several old IDI fords with 6bt's in them. Not sure on HP level, but a fair amount of fuel.

 

borg warner 4403 for the 96-97 i think the earlier ones had a 1356??


if i was gonna go slushbox i would go with a built e40d, yeah the allison is nice but dollar for dollar a built e40d will get ya alot further. alot of the high hp cummins guys are runnin e40d's

 

Dude, automatic cummins setups suck. Cummins motors love a stick. they sound the best with a manual to. Thats the route i would go if it was me. Now wether it be ZF or NV, I think i would go NV4500 personally. Good luck, post pics for all to drool over

Cowboy Steve

 

Well, maybe, but that is not what my research has shown.

Automatic cummins are also extremely fast, and a decent automatic suits the cummins well. I would also be hardpressed to say that a built e40d would outrun a built allison in speed or durability.

 

I'm not talking about a quad chargered, sled pulling, 10 second cummins here, hehe. I'd just like a mild cummins because there is nothing like a pre 79 ford that has the potential for 17+ mpg. I'll do some research on the dodge trans and t-case. As far as an auto sucking, its nice to just mash on the throttle and go. I wouldn't have a 5600 shoved up my $%#@# from personal experience. I still have a little bit to go, this project started with a 4bt that I scored for cheap and has turned into a 6b conversion with late model trans/t-case.

 

Thanks for the input, I am in the process of buying my 79 f-250 supercab 4x4 back, hopefully. Planning on using autoworld motormounts, nv4500 with advanced adapters part # 50-0220 and using the ford np205.