So the plan for me is to put a second gen 12 v in my 1974 chev truck. I have been reading up on it but i still have a few questions that hopefully u can answer. First off i am using the ctd with the dodge nv4500 transmission and i will be putting the chevy t case on the back of it so the driveline is on the passanger side. I found a adapter to make it from the figure 8 to the 6 round pattern. My question is are the chevy 6 round and a dodge 6 round the same size, spacing, exc. I plan on getting the dodge 23 spline input shaft to make them mount up. Second question is i have a mechanical clutch in the truck now how will i go about converting it to a dodge hydraulic clutch? Third question is can i just use my factory fuel tanks for the diesel instead of the original gas? How far should i box the frame back? Im sure there will be more questions when i get further into the project but thats what i have for now. Thanks for the help

 

I thought Dodge Diesel NV4500 was 29 spline? If I recall correctly, you could just use a Dodge NP205 from behing the First Gen's with the Getrag...that will be passenger side drop and bolt right up, I think.

You will have to fab up a firewall support and pedal assembly for a clutch master cylinder on the firewall for the clutch hydros.

I don't know about the tanks... And I wouldn't think you should have to box the frame unless its in bad shape or you plan on building a monster. Just be sure to build a stout crossmember.

Maybe someone with Chevy/Cummins knowledge can chip in...

 

I will look into it more about the spline but from what i have read most of them were 23 spline and the 29s were pretty rare in this year. The eason im using the set up i am using is because i got it for a good price. The t case on the older first gen has the figure8 pattern and wont bolt to the tranny i have. The truck is on 44s and its my mud toy its probably not going to be built too much but a little bit.

 

I have a Getrag 360 and a NP205 (both from a 1st Gen Dodge CTD) and it has an adapter housing on the t-case that is 6 bolt round and a double-female splined coupler to mate the male input of the t-case to the male output of the tranny. The NV4500 behind that Cummins "should" be 29 spline, and I'm nearly positive that the 1st Gen NP205 will bolt right up because I plan to do the NV4500 conversion in my truck and everything I've read on the conversions says it should be a direct fit. I could be wrong though...

 

Ya ur right about the 29 splines. I got a new input shaft for my t case, and the coupler. Im planning on starting the swap next weekend.

 

The fuel tanks will work, but I would recommend replacing ALL the fuel lines. And make sure you get ALL the gasoline out. I just got through making that mistake. Cummins dosen't run very well with ANY AMOUNT of gas,no matter how little.

 

Also i have heard the brake booster has to be changed into the hydro booster for room, what do i use for that? Will the dodge one fit?

 

As for the break booster all you need is the Hydro setup from a Chevy truck. I know they had them in the 80s. My truck has one. All the lines bolt right up to the Dodge power steering resivor.

You don't have to box the frame but if the frame is not a k-30 or c-30 frame it would be a better idea to. You really only need to box it to about half way under cab for it to be strong enough.

Like Farmerdude said it would be best to replace all the lines. And since you are doing that I would put a larger line in. Also if there isn't a return line already add one. There should be though. My 79 has one.

 

I am thinking of doing this same conversion or using 4bt or isuzu 4bdit, hp wil not be the goal mpgs will be the main priority. Anyone know what mpg with the 6bt, 4bt, or the isuzu 4bdit?

 

Do not use a 4bt in a full size. They're crap in full size trucks. You're not building a toy.

here is my conversion in my 81 chassis cab. Used all the factory dodge parts, even the gauges and they all work. I'm getting over 800K to 130L

https://www.dieselbombers.com/diesel...box-chevy.html