The perfect Cummins conversion?

[pwerwagn]

A while back my uncle built an exceptionally clean 84 1-ton 4-door with intent to put a cummins in it. he was eventually offered like 8K$ for the truck with the 360 in it, so It never happened.

I now have the chance to buy a 84 1-ton 4-door 4wheel drive for cheap. here are my plans. I would like to know what you guys would do different.

84 cab/bed/frame

93 front clip/radiator support/cummins radiator

96-98 215hp 12v cummins

DTT auto (I already have one 5-speed, and I'd like to try a DTT)

NV241-X-case

either use a ford Dana 60 front (to get driver side diff to match 241) or use a newer dodge 60 front and convert it to coil spring front end. (The dodge 60 front in the 4-door is going into my 74 power wagon)

My other option is to keep the stock 60 front in it and use a 205 case.

If I can find a complete 2nd gen donor truck, I may just try to use the entire running gear out of it instead (trans/case/axles).

Where is the best place to start looking for a 215hp 12-valve?

TIA



--Jeff

 

[DKarvwnaris]

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Where is the best place to start looking for a 215hp 12-valve?

TIA



--Jeff

At an auto auction where dealers are dumping the high mile or long in the tooth looking trucks. Buy an entire truck, you'll want the dash and harness for the diesel, not to mention the diesel fuel tank and filler if you can. I would look for a standard cab work truck as it will bring little to no money for the seller, but serve you well.

215 12 valve? any dodge with the p 7100 pump should do fine. I have always been interested in the older rotary pumps as they are becoming very easy to find these days with the cabs falling off the trucks.



When I am in need of a donor truck, I also drop my contact info at the local tow companies, especially in the winter when most accidents occur around here. One other thought, your state is on a dead even with mine for drunk drivers, check the impound yards or better yet, the parking lots of most bars, follow them home, they'll hit something. :-laf Sorry, we tend to treat drunks up here like stray animals.

 

[Don in Missouri]

The Diesel Fuel tank will not fit under the crew cab without modification. I was told the tank out a fuel injected truck with a short bed would fit.



I am using the original tank in my '84 crew cab, I do not have the fuel gage hooked up and could not use the Diesel, quick-connect fuel lines.



Doe the NV241 transfer case offer full-time 4WD in high range? That would be nice. I also liek the NP205 for nto havign a chain.

 

[pwerwagn]

Oh yeah, we treat drunks the same here too!! I have a few connections with local junkyards, towing companies, etc. I kinda like the P7100 because I know them, and I have a few plates already lying around. I like the 215 because it doesnt require any delivery valves or anything to be potent, just a #10. I will check on the fuel tank thing.

I too am a 205 fan, but I cant argue with the 241. Its quiet, strong, and easy to shift. no, there is no full time 4 wheel mode. Im not building a sled puller or a 1000hp monster, just a nice, reliable, fairly fast, family sized vehicle.

It may be easier like you say to find a 1st gen rotary pump truck. Then I can use the dash and stuff too.

 

[Trizae]

it sounds like you building my dream trucks,,,, only i'd use the 86-90 LE front end cause i think thats the prettiest front end ever on a dodge truck (2nd and 3rd gen included) but thats just me

 

["Mad Max"]

I can tell you what I'm doing and why, and that may shed some light. I'm also doing a DTT transmission, but I'm upgrading to a 2nd gen 47RE. Don't worry about the electrical stuff as DTT removes it all in lieu of their own modified hydraulic guts. What I found was a '98 47RE from a Cummins, and as well a '92 mated 205. I asked DTT and they are going to build me a bullerproof 1st gen overdrive, which will conveniently mate right up to the 98 47RE and also the '92 205 - best of both worlds. Plus, I'll have a lock up converter, and for me, that is everything.

Going that route I can also use an earlier dana 60 front diff that I already have. The truck won't be in 4wd often enough for me to need/want the shift-on-the-fly feature from the newer x-case, plus I wanted bulletproof 4wd, so that meant the NP205, hands down.

I'm also using a dana 80 dually rear from an '02 Cummins - bulletproof and it'll handle any amount of power I'll be able to throw at it.

The cost for the parts only hurts once, but you'll need the strong stuff, and for me I wanted strong and absolutely reliable.



For the transmission, you could find a non-mated old-school 205 and use a 2wd 47RE/H with an intermediate shaft. Same difference and finding a divorced 205 would be easier than finding a Cummins 1st gen 205. I have a friend in the salvage business that found both my 98 47RE and my 92 NP205. I can get you his number if you like - He'll find the stuff for you. My t-case cost $500 and the transmission, without the OD, was... ... (sheech... I'm trying to remember now... ) I think it was $850. Both need rebuilt, especially the transmission, but both are complete and solid. Depending on how far DTT goes into the transmission will dramatically affect how much it'll cost you to build it. If they go full boggie it'll be about $6k - but that'll give you a, literally, bulletproof transmission that you won't be able to break. The t-case will just need a rebuild - for a couple hundred bucks. I'm even going to rebuild my own.



Anyways, just my thoughts. Bottom line - for me, the transmission is everything. Skimp on the parts and you'll be building it again. Do it full blown the first time and you'll never get stranded because of the trans. The other parts you can usually limp back on, or at least to the nearest station... but the transmission - once it goes, it's gone.



- Sam

 

[Simplysmn]

HEY GUYS im in the process of doing a swap into a 85 crewcab and im useing a 93 as a donor truck so far everything has fit encluding fuel tank now mine is a long bed so it fit with no mods im useing a 93 core support rad, intercooler and things are looking good so far if i can help any of you out with parts that i have left over just e mail me what you need .



val

 

[SGibson]

why all the interest in fuel tanks? Will the "gas" tank not work?

 

[DKarvwnaris]

why all the interest in fuel tanks? Will the "gas" tank not work?

THe sending units and the filler necks are different. Gasoline filler necks are a pain fill at the diesel pumps, especially if you pull up to the truck pumps at times, its bad enough with the stock filler neck for the diesel version as it is. The other trick is getting the sending units and floats to work with the diesel dash panel, if you have donor truck and utilize the diesel dash and harness for the preheater harness ECM for the cruise etc. The access port on the gasoline fuel tanks are different, if I remember right on the older years especially, from their diesel counterparts. You can't just switch the pickup tube and float assemblies. Other than those reasons, which are plenty for me, its no big deal. If I was doing a dodge crew cab repower, I would gut the cab to its bare sheetmetal and utilize everything from a diesel truck, That way all you are having to worry about is driveshafts and a few lines not being long along enough. I've done a few like this and there was no way to tell the trucks didn't come stock like that. Since everything is a bolt in swap, why not? Replacement parts are easier to figure out too since everything is from one truck year and VIN except the second set of doors and seats.

 

[SGibson]

but there is no problem using the existing "gas tank" that's already in the truck,right?, it's a 78 stepside, the tank doesen't have an unleaded "flapper" in it and it's mounted behind the rear seat, it never kicks back at the pump handle when filling up unlike my 88 gasser which does it constantly, if this is what you're talking about. I mean diesel will work where gas was, right?

 

[pwerwagn]

Oh boy! I really would think twice about using the behind the seat tank. My 68 4-door had that, and my 77 macho has one, and they both have the vague smell of gas all the time. Imagine that with diesel!!!

The truck i am starting from is just the cab, doors, dash, frame, and axles. No motor, front clip, bed, seats, d-shafts, trans/xcase, etc. I bought it only for the dana 60 front originally.

I think I may just start searching ebay for a rolled/wrecked 92-93 cummins. Then find a 47RE and have it built by DTT (we have a certified DTT guy here in albuquerque). I still am unsure of whether I want to use the NV241 or the 205, though. I like the bullet proof part of the 205, but I like the low range of the 241. The 205 in my 74 also seems to make a little more noise than the 241 does.

I guess I'll have to weigh the pros/cons.

 

[DKarvwnaris]

Oh boy! I really would think twice about using the behind the seat tank. My 68 4-door had that, and my 77 macho has one, and they both have the vague smell of gas all the time. Imagine that with diesel!!! .

At least the diesel isn't as likely to ignite from a spark in the cab or a smoker.

I would never use those old cab tanks, no matter how good of condition they are in, or how much of a restoration I was going for. A farmer back where I grew up had a flat and rolled a truck with a cab tank. He had his window down, ended up soaked with fuel and nearly burned to death. He was unfortunate enought to be smoking on top of it. It was Horrible, he was in the burn unit for months. Somethings in the auto industry should never have made it past the design board.

 

[SGibson]

I have also caught the faint smell of gas in my 78 on fill-up, my 78 LRT had a tank under the truck so I don't know if it's a long bed or four door thing as to why it's behind the seat on this one and no it doesn't belong w/the hemi, torsion bars,or /6's as mopar highwater marks, My rear end from donor truck (in sig) is gonna req. fabbing to the bed and fenders to work,I guess I should start thinking of how to fit the 89 tank under the 78, I wanted to run a a-345 trans thinking it was a o/d and found out today it's just an extra low 1st gear w/4th being direct after scrounging the country for one. It would be nice to own one vehicle that when someone asks you what year it is you don't answer with "which part?"

 

[pwerwagn]

It would be nice to own one vehicle that when someone asks you what year it is you don't answer with "which part?"

ha ha! I hear ya on that! People always ask me the year of my yellow truck, I dont know how to respond. I usually leave the fact that it has Chevy axles out though...

 

[NSteever]

I went what I thought was the easy way. I used a 1991 Diesel 5spd 4x4 took off the cab stretched the frame and set a '84 crew cab on it.

 

[DKarvwnaris]

I went what I thought was the easy way. I used a 1991 Diesel 5spd 4x4 took off the cab stretched the frame and set a '84 crew cab on it.

If you feel comfortable/ qualified stretching the frame, which many folks aren't, its a solution too.



I prefer to use a stock frame only because it eliminates anything being modified beyond than the rear driveshaft and a few lines/wires. To put the crew cab on top of the stretched frame would still require stripping the interior out to swap out the dash and harness etc. Either way, you'll end up with essentially a 1991 truck when you source parts if you use the entire donor drivetrain.

6 to 1/2 a dozen I guess, good and bad to both methods.

 

[pwerwagn]

I feel plenty comfortable stretching the frame, but I feel that it just be easier to swap parts into the 4 door. I would also prefer to insure/register it as a 84 (slightly cheaper, not much).

 

[DKarvwnaris]

I feel plenty comfortable stretching the frame, but I feel that it just be easier to swap parts into the 4 door. I would also prefer to insure/register it as a 84 (slightly cheaper, not much).

I tend to agree with you, I don't know if ins. beyond liability would be worth it, they would most likely total the truck and give you a trinket toy for it in payoff. The newer year of the two may be bring you something more if someone else hits you. You could always insure it as a custom like the Centurion packaged Ford "suburbans" before the expeditions and excursions hit production.

 

[pwerwagn]

I have another question: has anybody used front seats out of a second gen (buckets w/center console) in the rear of a ~80ish 4-door? Im asking because Im wondering if there enough room with that seat, and still ample leg room for long trips. I found 2 sets of 99 seats (with the seatbelt in the seat) and I would like to use both sets. The front will be fairly easy, I've done that.

I found a 93 rotary pump motor with a Getrag and a 205 for a decent price. I might pick it up and then convert to auto later on (I have a spare trans tunnel).

Nah, i aint interested in paying full coverage for it. I believe liability is slightly cheaper on an 84 then on a 93. I know liability is cheaper on my 74 then it is on my 91, so that is what Im going by.

 

[DKarvwnaris]

Nah, i aint interested in paying full coverage for it. I believe liability is slightly cheaper on an 84 then on a 93. I know liability is cheaper on my 74 then it is on my 91, so that is what Im going by.

Check first, the liability on our CJ was higher than the wrangler we sold a few years back, Of course CJ's got a bum rap thanks to barbie dolls rolling them in the mall parking lots. We have higher limits on out policy now, but even with the same coverages, the CJ was higher. Depends on how many of models of a certain year were involved in accidents, stupid way to figure it to me



We had a customer with a old dodge crew cab that had buckets front and back. It was definitely roomier in the front, but his kids were in the back most of the time. It had more room than my 96 ext cab offers if that helps.

He also had the cab and box welded together so it looked like a suburban. The back came off like the old ram chargers. The seats were within the space of the crew cab though.