81 crewcab cummins swap project

[Bschwarzli]

OK. Let me see what I can do here to help ya! See below of what I learnt when I did mine:

Originally Posted by moparman89

GEE....I'm ready to pull my hair out on this project.....WHO EVER SAID this was a easy process!!! Alot of people seem to think that these 1st gen Dodges are all the same....yeah right! There are ALOT of different things from '81-'92!!!

Yup. Been there done that. ALOT is different!

I have been in the process of pulling the cummins/and tranny out of the diesel frame..pulled off the front springs from the crew cab frame...started to swap out the front and rear springs for two reasons...one to get more lift and second just because I wanted to be setup for hauling or towing.

Good. Progress.

I have had to swap out the tranny crossmembers...and have noticed there is a difference in the motor mount cross member...the crewcab one seems to sit about an inch lower?

I used the diesel crossmembers. Wanted to make sure I would not have any issues down the road. In theory if it sits lower, you will have an issue with the front axle to oil pan clearance if you ever needed to do anything.
Which shouldnt be a problem I hope! I also noticed they have slots on both sides one the diesel frame for the motor mounts? I'm just going to try to slot the other side on the crewcab crossmember?

Not following that one....

I have just found out that the front spring mounts use a bigger bolt on the very front and both mounts on the REAR springs use bigger bolts and the diesel truck!! So I'm thinking of torching the rivets and replace them with harden bolts and use the mounts and all?

Yup. Did the same. I used grade 8 bolts.

The rear end has a 6 inch block under the springs on the diesel truck.. is this factory? My crew cab had only a 4 inch block.

Always remember, everything was beefed on the diesel trucks. With your having had a 360 or 440 in the truck, it would not have been so beefy. My opinion is bigger is better.

Also noticed the front cross member is made different from the stock one on the crew cab? does anyone know why?

If my memory serves it had to do with how the rad core gets bolted on. I used my 93 rad core for intercooler reasons.

Anyone have any ideas on how to get out the upper front spring /bushings bolts?

Torch and big hammer. Seriously! For the bolts, and to get the bushings out, I used a hydraulic press.

Hope that helps!

Robert

__________________
1980 Dodge W350 Crew Cab Dually, 97 12V, PDR Towing Twins, NV5600, Gear Vendors, NP205, 4 Link rear
1990 W250 727, Reg Cab and 2008 2500 Mega 6.7 68RFE

[moparman89]

THanks guys!! Let me reword what I was talking about on the motor crossmembers....the lowest point of it hangs about an inch lower ..as far as the HOLES for the motor mounts they appear to be in the same locations at least on the passenger side...what I was talking about the holes (for the motor mounts)being different is on the stock 81 crossmember only one side was slotted...on the 92 both sides are slotted....but I'm going to slot the other side of the 81 so the motor will set level and make it easier to sit in there?
I'm going to try to make a paper template to make sure things are the same!

Does anyone know if you can buy aftermarket bushings for the factory springs?

ALSO on this fuel tank clearance issue..I am using a short bed...I know from some other post this creates a problem....my ? is how much clearence do I need 1".. 2"... 3" or how much? I'm thinking of buying a body lift....don't really want one ....but if it cures the problem then thats the way i will go. I have read where peole try to reform the tank with a heat gun...but will it stay?

[Bschwarzli]

Originally Posted by moparman89

Does anyone know if you can buy aftermarket bushings for the factory springs?
?

Yup. I just went to a spring shop andf they had them in stock.

Robert

__________________
1980 Dodge W350 Crew Cab Dually, 97 12V, PDR Towing Twins, NV5600, Gear Vendors, NP205, 4 Link rear
1990 W250 727, Reg Cab and 2008 2500 Mega 6.7 68RFE

[moparman89]

OK I GIVE UP!!!!!........I can't express enough how pissed off I'm getting....nothing is going right...I have been busting my but on this thing for past 3 days...I fought gettting the front leafs off the donor for 5 hours..I can't express how much trouble this process was...and removed the front crossmember just in case I decide to use it?...I sometimes wish I had NEVER bought this diesel truck...this thing has been nothing but a rusted piece of crap!!...some of the clips that hold the springs together were missing... this is what happened to one packs after i got it off....



OK..no big deal just buy a new bolt and put it back together...had to torch one bushing out of one of the packs..found a new bushing at Advance auto...so fianlly today I got the front leafs put onto the 81 frame...

then had a buddy come over and do some welding on the firewall...cut a section out put another back in for the slave cyl. and the electric junction thingy..and another for a grommet..THANKS NATE!!



Then FINALLY got the Cummins dropped in after having to torch a slot in the cradle for the drivers side because the mounts would not line up..


THEN the BAD NEWS....why DIDN't someone tell me I had to move the TRANS mount back about 1 1/2"s
After bolting up the tranny...and not to mention I even swapped out the tranny cross members so I would have no issues..


So I have two options I guess...REDRILL 12 holes for the crossmember mount...OR have a new plate made for the bottom of the transfer case to get the mounting holes to line up?

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Last edited by moparman89 : 11-08-2009 at 11:00 PM.

[Bschwarzli]

Sorry to hear that you are having a tough time with yours too! I have been there dude. For 4.5 years! Although I am almost done, I still run into issues with some of this stuff! Most recently my entire truck, fully repainted and had assembled, we found out my paint is peeling off due to faulty primer. The result? I have spent 2 months stripping interior, windows, everything off the truck so it is back to bare shell and dropped it off Friday for repaint. Was I p.o.ed? You bet I was! Gotta take it in stride though. Think of it this way. Not many of these trucks exist due to exacly what you are going through. Dont plan on finishing it on a set deadline (I am 4 years over mine! ) and take it day by day. We have all been there. And yes it does suck when you are "there". Keep your head up. Better times do come and when they are there and you are having that "I am so glad I started this project" feeling. Enjoy it. It will disappear soon!

As for the crossmember, sorry, did not know it needed to be. I drilled new holes in mine as I relocated it back by about a foot due to the NV5600. For you, I would do the same. Keeps everything balenced the way the factory did it.

Robert

__________________
1980 Dodge W350 Crew Cab Dually, 97 12V, PDR Towing Twins, NV5600, Gear Vendors, NP205, 4 Link rear
1990 W250 727, Reg Cab and 2008 2500 Mega 6.7 68RFE

[BRUISER]

Originally Posted by moparman89

So I have two options I guess...REDRILL 12 holes for the crossmember mount...OR have a new plate made for the bottom of the transfer case to get the mounting holes to line up?

I made a new plate for the bottom of mine.. it was easier and faster since I had the entire body still on truck.

[VortecZ]

Originally Posted by moparman89

OK I GIVE UP!!!!!

Yeah, don't give up. You are doing great. Just remember if it was easy, everyone would be doing it and it wouldn't be a big deal.

__________________
Daily - 2005 2wd Silverado with a Cummins 4BT & NV4500
Farm - 1995 4x4 Dodge Ram with a Cummins 6BT & NV4500
Toy - 1991 Camaro with full air ride, a built Vortec 350, & T56

[moparman89]

OK...so got a little good news today... a buddy is going to make me a new plate...come to find out its only off 1 3/16 inch...so thats not so bad..much easier!! I noticed on the back of this plate there is an area that is bent down on one side and has two holes in it..what is this used for..its not for the skid plate and I never took anything off of it? So we are going to make the new without it.

As far as having a deadline for this project there is none..BUT this project will be done before SPRING time..I
m not draggin this out for 10 years like I did on my 69 Charger a few years back! I'm working on this truck EVERY free day and hour I have....this is going to be my daily driver so it has to get done soon! The only hold up I will have is of course $$$$$

DO anyone know how much clearence I need under the back of the cab for that DIESEL tank? I have seen a post on this before somewhere but I can't find it for nothing..

Thanks guys!!

[Bschwarzli]

Originally Posted by moparman89

As far as having a deadline for this project there is none..BUT this project will be done before SPRING time..I
m not draggin this out for 10 years like I did on my 69 Charger a few years back! I'm working on this truck EVERY free day and hour I have....this is going to be my daily driver so it has to get done soon! The only hold up I will have is of course $$$$$
!!

I mean this in the best possible way.





You sound like me 4.5 years ago!

Did EVERY night, weekend, holiday etc for 3 years, then a slowed down a little.

Seriously though, it can be done if you put your mind to it!

As for the tank, you looking for deapth or length?

__________________
1980 Dodge W350 Crew Cab Dually, 97 12V, PDR Towing Twins, NV5600, Gear Vendors, NP205, 4 Link rear
1990 W250 727, Reg Cab and 2008 2500 Mega 6.7 68RFE

[moparman89]

I thought I read once there was a clearence issue with the top of the fuel tank and the back of the bottom of the cab? I was going to order a body lift...but not sure which to get a 2 or 3 inch...to avoid this issue? But if its not a problem I might not get a body lift? so my ? is how much clearance do i need to clear the tank?
I read somewhere that a guy took a heat gun to the tank to reform it a bit?

[johny5]

Looking good ,
I would just drill 12 new holes for the for the cross member.
as for the fuel tank the original tank works fine , I just lost the low fuel light.

__________________
currently building 85 crew cab with 93 cummins 5 sp

[moparman89]

johny5...thanks...I don't know if you did or not,but I'm using all the wiring from the '92 truck,and I want to use the diesel tank because it will hold more fuel....but if I use the stock tank,I'm not sure if I can use the factory wiring from back there up to the cab........I suppose I will figure this all out when I get to that point.