hi guys.. need some help and advice . i have a 1985 dodge w350 crew cab.. has the np205... np435 granny... dana 60 front and i think dana 70 rear.. what year donor trucks should i be looking for? intercooled or non intercooled?also would the np435 be a good match for the cummins? or would it even work? and any general advice on the conversion itself if anyone has done one like this..on what to look out for etc.... thanks for the help.........

 

I would be suprised if the crew really does have a 70 rear. Most just had 60 rears. If it does indeed have a 70 rear, look and see if it has 35 spline axels. The 3/4 ton first gen diesels have 32 splines that are smaller diameter. The 4spd IMO will not like being behind the cummins, and does not have OD, you will want that. I would find a complete first gen, 91.5 to 93 is better cause they are innercooled, but I would not be scared of an 89-91. Then use the complete drivetrain, engine, trans, tcase, radiator, rear diff and front diff-if the ratios are differnt in the diesel then the crew. Then sell the 4 spd/205 the extra axels, and whatever is left to me for my gasser pulling truck.

Michael

 

Keep us posted I have a 1975 Crew that I want to convert someday!!

 

If its a W350/10000 GVW it should have a 70. Thats part of what makes it a 10000lb truck.
As far as what years to look for, I was able to put an intercooler behind my '83 grill with little modifcation See my photos. So my vote is 91.5 -93. Depending on how you want to do the conversion on what type of mods you will have to do. I went with the complete motor, Trans, Fuel and elec system out of a 92. It required me to do some small firewall mods. and a core support mod (modifed the 92 support headlights mounting, moved in and down to fit the 83 grill) PM me if you have additional questions
Bill

 

Those are some sweet toys!!! Do you have any wiring diagrams for the conversion?

 

Good luck with it. My '75 conversion runs like a top. The 1st gen is the simplest, but for my next project I'll probably look for a 12 Valve for power.

 

Nope, where I removed it from one truck I pluged it in on the other. I wish I had taken pictures durring the process but I never think of it at the time.

 

thanks for all the input guys.. now if i could just hide the project from my wife..lol... where are some good places to look for some donor vehicles? do i really need to swap out the axles? i know i have 4:10 ratio in the crew cab.. i will run atleast a 33inch tire.. so that should lower it some..

 

I was lucky and found my donor right in the classifieds on this site. Thanks DTR!

 

*If* indeed it has a dana 70 rear and it should have a 60 front, then no you don't have to swap the axels. If it has the 60 rear, then that will be very marginal and you will want the 70 rear from a donor. If the front dana 60 is geared the same as the rear then the original will do.

Here is my opinion on the 410. Please note this is my opinion. I think the 410 and a cummins is a pretty slow gear, UNLESS you tow alot and heavy. I run upwards of 29,000# gross weight with 3.55's, and 305/70R16 BFG's. It is kinda tall getting the load rolling, but I can still run OD on the interstate. 33X12.5X16.5s are a little shorter, and my truck runs better with them on it while towing. Empty I see no need for 410s. Now, if thats all you got then it will have to do, it will just turn more revs at speed.

Michael

 

PeteRR did you change the wiring in your 75 cab to the 93? IM working on a friends 75 crew that some did a conv. for and chopped the hell out of the wiring. Im in Sacramento Ca and finding a wiring harness for him is killing me. this truck has the 93 engine harness (if you can call it that anymore) and a 1/8 part of the 75 harness for the cab.

 

Yeah, we junked the '75 and used the relatively good '93 harness. The '75 had been hacked and modified many times.

 

same here and trying to find a harness to use is like pulling teeth everyone wants to sell me the whole truck if they even have one. did you keep the 75 dash and gauges? i was noticing that the plug for them look alike