does anyone have any pics or diagrams of the mods and necessary fabrications needed to swap a 96 12 valve into a 79 3/4 ton 4x4 chevy? Any other info would be a big help as well.

 

its pretty straightforward, your hardest part will be getting the T case dropped on the right side, I'm fighting that on my setup. Can you fab? Engine crossmember + mounts. There's a company out there that builds a drop in crossmember with mounts, I can't remember what their name is.
This is how I set mine up, same idea. Also you've gotta figure out your cooling. I don't know what the clearances are on the OBS. I ran a pair of flexilites that are more than enough with the 6.5 rad.
I don't have any specifics on that particular setup, but on mine I basically measured everything out to be even and have enough clearance for cooling, etc. Basically tried to get as much clearance everywhere as I could, fabbed up my crossmembers and mounts, then put everything else together around it.




Seriously, biggest most expensive problem IMO is getting the passenger side drop. I have a chev mainshaft in a dodge 4500 with a NP241C out of a mid body style change suburban, with a turbo 400 input shaft and a custom machined adapter to the dodge tailshaft housing.
You gonna do auto or manual? Auto really would be easier on this note, cuz the 23 spline np208 is a lot easier to find than the 29 spline for the 5 speed. If your doing a manual, do yourself a favor and put a cummins input in a complete chev trans w/ t case.
The exception is if you can find a getrag with the 208 with it. If you can't find the 29 spline 208 and the coupler with it, don't even bother. They are a needle in a haystack and then expensive as hell if you do find one.

 

I can fab the mounts and all that stuff, just thought a visual would help. I was thinking about puting the radiator in the bed like they do on alot of mud trucks and running elec. fans. that would make more room and is easy to do. Could i just get an adapter for the trans in the chevy and just use it. i would the think there is some other things that have to be changed dont really know what though. Did you have to notch the frame for your starter? And is there any certain amount of lift i will need?

 

I can't tell you about clearances on that body style, but I think its about the same as the front of mine. It might be tight down low, but I'm not sure.
What chev trans do you have? Also whats your rear end ratio?

The cooling in the bed would work, but I don't think you need to go to those lengths, it can definitely be done inside the engine bay. Here's that pre fabbed setup, Avalanche Engineering. Overkill IMO but I guess if you have the money you could go that heavy. Most conversions work similar to this, that they use the rubber block isolators off of a 1st gen cummins instead of the long mounts with the round bushings on the 2nd gen.



1980 K30 Cummins - Diesel Engine Conversion - Diesel Power Magazine
There's an article of one in an '80. not many details, but gives you an idea of what it can look like.

 

im pretty sure its a turbo 400 i havent even looked at the pan and i was told by the guy i bought it from it has 3.73's. I havent had anything apart to give you a solid answer. As far as spending money on the mounts, never going to happen! Maybe the adapter for a trans. but im working on a pretty tight budget, i mean no budget. thanks for the pics they gave me a pretty good idea of what to do.

 

Where is the vacuum modulator on your trans? Is the trans pan relatively small or long rectangular type? The larger one is a TH400. Here are some pictures of a 1984 K20 with a 5.9 from a freightliner FL70. This engine has a front sump pan, the dodges have a rear sump pan. This truck also has a 6" lift and I had to add a 3" body lift to be able to use the ford ZF5 speed. You do not need the body lift to get the 5.9 in there. I had it in there and ready to go without it until I recieved my engine plate and had to change it. Here are some pics.




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I used 1st gen engine mounts on this one. I left the engine stand mounts from the stock cross member and then used 1/4" wall 2"x3" tubing and built a new crossmember and it bolts in like the factory one does. Then I modified the stock crossmember for the trans and made it possible to bolt the ZF5 2wd trans in there. This is where this truck was left at. I am thinking of putting a 205 on the ZF5. I was going to use a divorced 205 but I don't want horrible drive shaft angles. On yours you can get a first gen 518 and 205 or a get rag and a 205 and the drive shaft will dump on the same side. If you get the getrag type 205, you can bolt that on a Dodge NV4500 as long as it has the 29 spline out put shaft.

 

thanks for the info, id like to see the pics if you finish it.

 

It's at the body shop and has been for a year unfortuanately. The crew cab in the backround is getting one as well. Hopefully in the next few months.