Sunday, March 22, 2004  -  I made another run today to the salvage yard I was at last weekend. Before I left last time, the owner said he had what he thought was a 390 that was in a '74 F-100, and it was a running vehicle. I  did a quick check of the stroke to verify that it was a 390 and not a 360, and when it was indeed determined to be a 390, I told him I wanted it. He agreed on a price of $75.00.

I got started disconnecting the engine about 10:30 AM and had it ready to pull by about noon. I was amazed at how easily everything came apart...even the exhaust pipe connection at the manifolds just unbolted without breaking any studs! We latched onto the engine with his front-end loader and  yanked it out...after a quick pause to disconnect the shifter linkage which I'd forgotten to do. (I always forget one thing when I do this...and it varies each time!)

When he asked me if I wanted him to set it down so I could disconnect the tranny, I made the decision right then to just take home the C-6 as well. Not only was it easier at the time, but it turns out the tranny had a slip yoke in the transmission tailshaft, unlike most longbed trucks which had a bolt-on yoke and a two-piece driveshaft with a built-in slip coupler. This '74 still had the two-piece driveshaft like normal, but had a car-type transmission with a shorter slip yoke. I was able to grab a regular car-type slip yoke (which is about 3-4 inches longer) to use for my project.

Fig. 1  -  Here's the '74 F-100 about to undergo an engine-ectomy. Notice anything strange about this truck? Look closely!

Fig. 2  -  If you were able to pick out the '72 box on this '74, you've got good eyes. A previous owner minimized the obvious differences by slapping on some universal trim molding. You might not even notice it at a quick glance. A hole was cut into the bed behind the left rear tire to accommodate the fuel tank filler.

Next it was on to removing the complete power disc brake setup. In Fig. 5 above you can see that the proportioning valve is located immediately below the master cylinder, unlike the later Ford trucks which had these mounted down on the frame crossmember. Utilizing this setup would make it much easier to hook up a manually-adjustable proportioning valve in the future.

I DID find another interesting tidbit. The power-booster-to-brake-pedal linkage was a bit different on this truck compared to other trucks I've seen. All '67-'72 boosters I've seen and the '79 booster I pulled several weekends ago had a rod coming right from the back of the booster to connect to the brake pedal. This booster, however, has a pivot system in the bracketry. The booster rod enters high and the brake pedal rod enters lower. This bracketry setup will have the assembly sitting higher in the engine bay and appears to be designed to allow extra clearance between the engine and booster/master cylinder for V8 engines. However, I'm just speculating.

The D2TEAA (with the 'T' standing for 'truck') cylinder head casting numbers are located in between the two middle spark plugs. These '72-up emission-era heads have a little smaller intake runners that are good for low end velocity and torque. From what I understand they are essentially the same as the C8AEH castings from my '68 360...both are considered 'low-exit heads' and have 68-71 cc chambers, both have standard small FE valves, and both have the same port sizes...except that these later heads have induction-hardened seats for running unleaded fuel and cooling fins in the water jackets. From what I've learned, they have great potential, but they do need some work. For use in performance applications, CJ-sized valves (2.09 intakes and 1.65 exhaust) are recommended, as is a porting the exhaust bowls, mainly in the roof area (since the roof has more flow than the floor), to flow a bit more air.

From  my online research, here's the general consensus for the do-it-yourselfer: Bowl porting under the valve is your biggest gain...just do some reshaping and smoothing, never polish the intakes. You can polish the lumps in your intake ports (one lump per head), but don't grind much on it. There is an oil passage in that lump that feeds oil to the rockers. Get rid of the bump in top of the exhaust port. Don't port-match the exhaust but try port-matching the intake using a Fel-Pro FP1247 gasket. Bolt on the heads with head gaskets, bolt on the manifold with the type of gaskets you will be using and mark reference points on the gasket edges and head so when you take off the manifold you can set the gaskets on the heads and mark the port outline.