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Hey all.
Bought a 1984 D250 more than a couple years ago now. Small block, two barrel carb, three speed auto transmission. The thing was a thirsty pig, and almost incapable of getting out of its own way. But I liked the styling of the old Ram pickups and is relatively rust free. I had a Cummins swap in mind as soon as I bought it, and merely waited, fixing minor things until the trans puked third gear. Drove it for almost a year like that until gas prices skyrocketed and I got tired of not being able to go anywhere by highway. Parked it and borrowed my grandad’s car for a couple weeks while I kicked around some ideas as to where I might get my hands on a 6BT and a manual trans.
Craigslist pulled through and I purchased a 5 speed 6BT swapped 1991 F150 from the second owner, the first owner being the one who had a Cummins shop in Minnesota do the install back in 91. I’ve been driving around in an absolutely clapped-out Ford for the past couple years after I sold the 318 and trans and began collecting parts.
I’ve installed new/beefier front suspension parts, steering bits and ball joints, new brake rotors and lines, wheel bearings.
What I haven’t done yet is cut the firewall for the clutch pedal or taken apart the steering column/dashboard to get the gear selector out.
Some parts I need to buy yet are the motor mount brackets, but I believe I read it here that the dealership should have them or be able to get them.
Some extra details: it is a Cummins engine not a Dodge Cummins. There is nothing on the engine that says Dodge. Hell the entire engine is painted Cummins brown. There is an aluminum five speed trans with Ford markings bolted directly(afaik) to the engine. So I will need a custom driveshaft made and to mount the Ford’s trans brace to the Dodge.
Got the dashboard apart, gauge box out and the steering wheel dropped this weekend. Debating if I should pull the wheel and steering column completely, I made a template for the four holes I gotta drill for the clutch bracket but it looks pretty tight to go at it from either side with just a regular electric drill.
Got the clutch pedal, master cylinder and bracket installed this weekend. Question to those who have done auto to manual swap. How do you wire from the neutral safety switch to the wires from the master cylinder? I'm assuming those wires are the "clutch in to start switch"
Thanks Farmer! I figured it should be pretty straightforward, I just have a hard time wrapping my head around electricity and circuits. Which is nice with the mechanical Cummins, I can pare my wiring harness down to illumination, starter solenoid, fuel solenoid, gauges and radio. Slowly but sure progress.
Ran into a bit of a snag. After checking with the local dealership, the motor mount brackets are a discontinued part. Is there a company that makes these brackets brand new? If not, for those of you who have swapped a Cummins into a Chevy or Ford, did you happen to save the brackets? Not sure if I should start a "wanted to buy" thread but these are the parts I need. Circled in green.
Getting close, but this kinda took the wind from my sails.
Been awhile. Been busy.
Engine and trans are in the Dodge.
Rear disc brake conversion finished, all new brake lines front and rear.
Wiring harness is pulled apart, got rid of unnecessary wiring from small block sensors.
Will have to fabricate a dual battery tray on the passenger side, that's where the starter is on the Ford trans.
Installed new clutch and pressure plate when engine and trans were separated.
Exhaust is about half complete. I think I want to run a stack, just have to commit to cutting a hole in the bed.
Still have to graft the Ford floor pan into the Dodge for the trans hump and to address some rust spots/holes.
I need a u-joint that's half Ford trans half Dodge driveshaft.
I also need a Dodge lower water neck, the industrial Cummins points straight forward and down at 45, would need a really tight, one-off "S" bend hose to attach to the radiator. Stock water neck points straight off the block and I'd be able to use stock hose.
So yeah. I'm pretty pleased with what I've been able to do on weekends and between 17:00 and sunset after work. Hopefully there is one last stretch of decent weather to button up the stuff I need to crawl around under the truck to do.
This website has been an absolute godsend while trying figure out how to do something, seeing how others have done similar. Thanks all!
As she sits and what I've done this year.
The Ford transmission brace is bolted to some angle steel that's bolted to the frame.
I was able to use my original Dodge driveshaft, got a combination u-joint that is half Dodge half Ford and got a Ford slip yoke half an inch longer made by a local driveshaft shop. So far no odd vibrations or clunking/binding sounds.
I had to get two new wheels, as the fronts were not original to the Dodge. They did not fit over the rear axle hub, I am assuming they are from a Chevy with 8 on 6.5 lug spacing. Also got some brand new meaty tires.
Rear disc brake conversion was done last fall, I cannot stress how nice it stops now. I could never get the drums adjusted right and they were always grabby and lock up hard. I could hop out after a hard stop and the front rotors were not even warm to the touch. I haven't really panic stopped yet, but even a normal hard brake does not lock up the rears. So I'm pleased as punch with that.
I cut the radiator support when I was putting the engine in. Even with the hood off I could not maneuver the engine and transmission in over the front clip. Made some brackets to hang a stock radiator to. I was able to use the stock lower radiator hose and a universal hose that's about 2 inches longer than the stock upper cos my upper water neck comes out straight up instead of at an angle.
Got all the gauges wired up and cut a hole in the bed for a stack. Exhaust is 3 inch flex pipe from the turbo under the cab until it joins a 90 bend than straight up about 5 feet.
I modified the fuel pick ups in the tank to run a larger hose. The fuel gauge acts a little funny so I might have to clean up the plug contacts or swap the whole thing out if its part of the float sensor setup.
I ended up having to swap out all the steering and suspension parts and ball joints and lower control arms. 3300 pound axle stuff is not compatible with the Cummins drop center link steering assembly. Oh well lesson learned.
My floor pan is a murder scene, but my cousin has friends who race dirt track stock cars. So one of these days, I'll see what they can do about welding up a new trans tunnel and replace some of the more rotten areas of the pan.
So that's about it. I gotta get a headlight yet and a front turn signal bulb and figure out why both rear turn signals flash when I signal a turn in either direction.
Big shout out to Deere Country and Oliver Foster for having the parts trucks to keep these old rigs on the road, and to the forum community itself. The first gen forum is an absolute goldmine of knowledge.
06-23-2015, 03:47 PM
