Letter Re: Re-Engining an Older Ford Pickup with a Diesel Engine?

One of my long term goals is to own a diesel pickup. A mechanic friend of mine down in California, a true Ford guy all the way thru would say that the time tested and proven International engine used in the the Ford pickups was the most reliable–with the Cummins running a very close second (It should be noted Ford owns a controlling interest in Cummins and Ford does/has used Cummins in several of their industrial projects, including farm equipment and heavy duty trucks). I don’t know all the details but I will say that from my own experience the Ford/International trucks, namely the 6.9 liter of the 1980s was a long-lived engine. I once was at a Ford dealership in southern California when a fellow brought in a 1986 F-250 non-turbo 6.9 liter diesel to ‘trade-up’ to a more modern pickup (this was in 2000). His truck, which he claimed had never gone thru a rebuild, had just had regular maintenance had 688,000 miles on the odometer!
The guys at the dealership were astonished and even mentioned contacting the corporate headquarters to use his story as an example of Ford reliability. I myself own a 1973 1 ton GMC with the very reliable 454 gas engine and I have given serious thought to pulling that out and sticking in a 6.5 Diesel. I would more than likely go from my present 9-10 MPG to 15-17 (even with a 3 speed turbo 400 tranny behind it.) If there are any folks out their giving this consideration (those of us with older pickups) they may want to consider this as an option and if they are running an older 3 speed like a turbo 400 or Ford C-6 and they want better highway performance, look into ‘Gear Vendors’ over/under drive. See: http://www.gearvendors.com/index.html. This, I’m told, will turn that old tranny into a real highway cruiser. Story has it that the guys on the hot rod circuit and at the drag strip swear by ‘Gear Vendors’, they are rated at handling 1,200+ horse power! Hope this helps someone that is hanging onto there old pickup but wants the reliability and performance of the newer rigs. Thanks, – Jason in North Idaho

JWR Replies: If your 1973 Ford still has a rust-free body, then it may be worth doing. To achieve full reliability on a truck that old will probably require a lot more work than just re-engining. Read: extensive and expensive.  (For instance: a new wiring harness, rebuilding both differentials, a new drive shaft or at least new U-joints, re-arching the springs, considerable other suspension work, possible steering work, new master cylinder, new radiator, et cetera.) When all is said and done, you might be better off finding another 1 ton 4WD that was built in the the early to mid-1990s with a dead engine as your starting point. Rebuilding a 10 to 15 year old vehicle is a much less daunting task that rebuilding one that is 32 years old! Once a rig is more than 25 years old, it generally requires a true “zero time” rebuild.  Again, that is extensive and expensive. In the interim, you can use your running 1973 until the project on the “new” pickup is done, and then sell it off. Just my $0.10 worth–“your mileage may vary.” (YMMV.)