Not to confuse seeing the light at the end of the tunnel with basking in it, but the F250 appears to be nearing road readiness. Only 2 big jobs remain: plumb the clutch hydraulic system, and plumb the fuel return system. These last few weeks have been helped along not only by the need to accomplish and subsequently yak about something more substantial than a drill chuck change, but by access to a lift.
I have yet to do anything that can’t be accomplished without one, but the increased space seems to result in increased blood flow to the brain. You can see everything whole, just like the topside, and piece together solutions, like resolving that 5 degree mistake in the outlet of your custom downpipe that you might have blown off because of the darkness and misery in a world without lifts.
The whole mess of parking brake cable can be seen at once, and an easy solution to securing it all becomes readily apparent. For me, that’s much needed progress on a project which I’ve honestly come to regret undertaking.
About that: This is the second engine swap for the Avocado, which I got off Craigslist for $1,200. The seller had trouble getting it running right and was unable to put more time and money, the usual story. Nonetheless, we were able to get its rebuilt 390 running long enough to get it onto a trailer, and I felt like a carb change would make a driver of it.
It wasn’t long before an inspection turned into yet another case of While-I’m-in-theres. There was just too much oil everywhere to not be curious, and I decided to pull the engine to clean and reseal it when I discovered that, among other things, the rear intake seal had come out completely, and there was a full 1/8 or so gap for the motor to blow oil all over the bellhousing and everything behind it. Well, if the engine was out, I might as well flip it over and pull a bearing cap. In doing that, I quickly discovered that the bearing was shot, there was residue everywhere, and this rebuild was not worth using.
And it took the machine shop equally little time to determine that just as it wasn’t usable, it wasn’t rebuildable. They summoned me to run an eyeball down the length of each connecting rod. There were all bent. The consensus was that the previous rebuilder’s boring machine was not quite perpendicular to the block, and the second the engine turned over, the rotating assembly too was ruined.
Undeterred, I found another block and ended up with a solid running 390 that howled as intended – and pulled it after driving it about 6 months. As the truck has been down for roughly 3 years since, I no doubt regret it. I wish I’d addressed the fuel mileage and drivability woes with an overdrive – which I had sitting in the garage – a rear end change, and an aftermarket fuel injection system. I’m clinging to the faith that my opinion will change with the new setup that has kept me going since.
The “new setup” is this:
- Cummins 4BT engine. Little brother to the 5.9 that came in all those Dodges, this came out of a step van and produced somewhere around 105 horsepower in that van. But:
- HX30 turbo upgrade with intercooler. I didn’t do a lot of engineering here, my love for turbos is large but not enough to digest boost maps. This is a common and recommended upgrade for this engine. The intercooler is a Mishimoto model that, unlike every other Mishimoto intercooler I’ve ever seen, is affordable.
- Borg-Warner T19 transmission. This came with the engine, and also came in a bunch of Ford 6.9 trucks. Better than the T18 because first gear is high enough to be a functional first gear.
- Advanced Adapters Ranger overdrive. Thematically, found on Craigslist. It was setup for a Dodge, but Advance Adapters was able and willing to sell me the parts to mate it to a Ford-spec drivetrain. I had a Gear Vendors, but GV was adamant that while it was no problem to handle the power of the 6BT, the vibration of the 4BT would be its Waterloo.
- Rear axle swap. The Dana 60 originally under the truck had a 4.11 ratio. The noise and fuel mileage got old. What’s in there now is a limited slip Sterling with a 3.55:1 ratio out of a late 80s 1 ton.
The truck has some other mods which will get a few seconds on a video: fuel tank upgrade, fuel inlet changeover to a later year, new shifters. But overall the intent is to keep it looking the same. Nonetheless, the 2 jobs mentioned above are accompanied by a huge list of smaller but time consuming tasks:
- redo an engine mount weld that looks insufficient
- Cut out some inner fender to make room for the new fuel inlet
- install some folding mirrors
- configure the overdrive shifter
- sound deadener and flooring
- mount the rear bumper
- trailer brake controller
- reinforce intercooler mounts.
And that’s to get it roadworthy. To finish it would be another project.