96 crewcab dually cummins swap

So i had a lil change in the priority order on my project, basically i couldnt figure much out without having the cummins in place before i did anything...b/d, front clip swap...etc

i picked up another OT truck that needed a BBC, so i figured why not.

the truck as i got it last weekend.




the gas motor out and 12v cummins/a518 trans first test fit.


about 4" to the firewall, and it could go back further if i inteded on keeping the mechanical fan, but the trans lines up extremely workable to the stock trans x-member by placing it here.



and since this info is extremly hard to find anyplace on the net, this is the important stuff for anybody with or plans on this swap in a b/d/bagged truck. where i have it sitting right now, the stock unmodified pan is the same as the front crossmember, and the front valve cover has roughly 1/2" of hood clearance.



and the first issue i ran into getting the motor set in place, the cummins a/c mount/braket will need some trimming to clear the idler arm. once this is out of the way, i will drop the motor about 3", and work some magic on the pan sump.

Nice, when all is said and done can you tell us how much the added weight lowered the front?

i was gonna make sure i measured it BEFORE i tore it apart..... but i forgot. figure its only 400# give-r-take more

Absolutely love this build! !!!

I like where this is headed. You may want to slide that motor back as far as possible. I think mine is about an inch from the firewall. I'd also recommend against electric fans and lowering the motor any. The clutch fan will do way better cooling the engine especially when pulling. I'm actually looking for the dodge serp belt parts to get rid of my electric fans.

I put a piece of a 2x4 on my engine crossmember and just set the engine on it when I made my motor mounts. I didn't have to cut my pan at all.

What gears are in your rear axle?

here's my thread. Any questions just ask.

i found your build thread a few days ago, added fuel to the fire to yank the gas motor before i started driving it.


i have the motor sitting on a 2x to the crossmember now, but the main reason for dropping it further is the planned b/d. i have about 3" from the pan to the bellhousing, and by sectioning the pan i can get it that much lower... the pick-up tuubes are easy to shorten, and by making it shallower and wider(think circle track or drag race sbc pans) i wont lose any oil capacity. i dont want to go back any further, i need the firewall clearance for my future turbo set-up, which will be a duo of parrallels, into a single compound, with a flowed p-pump.... this is all goin onto another 12v i have at the machine shop now.

the cooling issue is something i have gone back and forth with a lot.... "if" i was planning on hauling a wedge, and actually using the truck.... i would prob go that route... but this is more of a DD, use it to haul my 2700# fox mustang to the roadrace tracks, in a 24' enclosed. im pretty confident that 2 14" elec fans in a shroud should do ok....and if not i will cross that bridge when i get there.


as for gears, right now it has 3:73s i think, and with a CC 14 bolt rear, the tallest i can find is 3;42's, so im lookin at something for a double OD, but i really dont want any extra levers, i doubt a gear vendors will hold up to the tq.... i havent had good luck with them in the past in much lower hp gas "hot rod" applications.

I'm planning on b/d my eventually too. I'm probably going to have to run a cowl hood or something. my engine angle is great and my tranny pan is still above the bottom of the frame. I'd just route your exhaust before you build your pan. with the turbo setup you're talking about you'd need atleast 4" out of the turbo.

I'd set the motor so you can use the mechanical fan if need be. I have a 16" and a 12" electric fans on mine and it still seems to run hot. And that's just daily driving. It's alot easier to do it now then later.

I think most dodge trucks came with a 3.52 rear end so a 3.42 would probably not need a second overdrive. I wouldn't trust a gear vendor either. That's why i went with an old Brownie 3 speed. they were used in 2.5 ton dump trucks and crap in the 60s and 70s so it should hold up fine. it's a big ass trans though. I still don't have the shifter hooked up for it.

looks good man. anymore progress on it?

havent touched it, i work 4 12's at work, then a couple hours in my shop. this project is in my garage at home, so i wont be tempted to work on it when i should be workin on the last few "other peoples" projects.

i have been ordering parts, i ordered 4" oval exhaust tube...which actual size is 2.75x4.5" i should be able to snake that over the trans crossmember and leave enough room for the stock floor b/d. i wanted to run 5" oval, but cant find it anyplace. i may build a mandrel roller to do 5" SS round into oval in the future... but the 4" will be fine for now.

i also ordered the 05-06 sierra front clip parts...... i plan on grafting the fenders and using the whole hood...sans sectioning the width. this should give me 3-4 more inches of hood clearance. and it lets me mount the intercooler behind the bumper...with all kinds of extra radiator room. i am strongly leaning towards a dual crossflow nascar style rad, they are smaller but way more efficient than the oem big block unit. i can probably push it all the way"into" the core support opening which would leave plenty of room for the mech fan.

the UD/OD is a down the road project.... i would love to use a brownie set-up if i could figure out a air cylinder to shift it.... but with the auto, that may be hard

not much of an update, been spending lots of time with the FSM weeding out everthing i dont need for the diesel. ordered a few interface items from dakota digital to make the tach and speedo work. decided to go ahead and domepiece's advise and set it back for the machanical fan.... but im waiting for a 2nd gen 12v 4" downpipe to show up before i finalize the engine position.

cant wait to see this beast in action !!