Ford to Dodge?
Posting Guru
Joined: Jun 2000
Posts: 1,229
Likes: 3
Freshman User
Joined: Dec 2003
Posts: 30
Likes: 0
From: Big Horn, Wy.
We've done two of these conversions, one in a ranch truck, and another in an employee's truck. Cost kind of depends on how much of the work you're willing to do on your own, and whether you're planning to modify the engine. the fordcummins site is excellent, but when we did ours, it seemed that we only needed a few of the parts they offered, we built mounts and all the labor ourselves. Both projects cost between 3 and 4k, but were very successful. The 12 valve engine is by far the easiest to use (no comp, and only 1 wire actually needed to make the thing run) but I've heard of people getting ambitious and using computerized 24valves. I won't lie to you; it's a real project, and not to slam ford engines, but the Cummins will outperform whatever engine you have in your '90. If you're comfortable taking something like this on, do your homework, and don't look back: You'll be thrilled with the product.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
I have a 7.3 IDI turbo 4 speed in my 86.
I broke the driveshaft and transfer case on my truck pulling a 16,000 pound trailer when road work stopped me on a 12% grade. When I went to take off....BANG.
I drove a friends 2001 3/4 ton dodge with the 5.9 24 valve Cummins and a 6 speed tranny.
Pulled the same trailer with his truck which weighs about 1500 less than my Ford.
I was impressed with the six speed.
I was not impressed with the 5.9 Cummins.
Even with the six speed it did not pull like my 7.3 IDI turbo and a 4 speed.
Both engines are at stock fuel settings.
I broke the driveshaft and transfer case on my truck pulling a 16,000 pound trailer when road work stopped me on a 12% grade. When I went to take off....BANG.
I drove a friends 2001 3/4 ton dodge with the 5.9 24 valve Cummins and a 6 speed tranny.
Pulled the same trailer with his truck which weighs about 1500 less than my Ford.
I was impressed with the six speed.
I was not impressed with the 5.9 Cummins.
Even with the six speed it did not pull like my 7.3 IDI turbo and a 4 speed.
Both engines are at stock fuel settings.
Freshman User
Joined: Dec 2003
Posts: 30
Likes: 0
From: Big Horn, Wy.
We found that the Cummins RPM difference is really not that noticeable if you run 3:55 (or higher) gears. With iether the 5 or 6 speed behind a 12 valve engine, you can cruise at 75 at about 21-2400. I believe all stock 12 valves were governed at 2500, so 3:55 gears are about a must for a stock engine. Modded engines can use the lower gears, but those RPM's really don't get you more power. In fact, above 2400ish, power and torque basically flatten, and fuel usage spikes much anywhere above 2100. If yer in for a project, take a 12 valve, gear it to do 75mph at 1950RPM's, and then replace injectors, cam plate, and do custom exhaust. Everyone else on the road'll have to step aside! 
