Ask Away! with Jeff Smith: Crate Engine or Junkyard Rebuild for a First-Time Engine Build?

I have a ’72 Ford pickup that I’m slowly upgrading. It was originally a 6-cylinder truck and still has the original automatic I want to build this truck as a fun father- and-son project so I’m looking for suggestions. I’m thinking that a small block wouldn’t be a bad way to go. We don’t need a lot of power – I want him to learn responsibility before we go with a lot of power. But having said that, it still should be fun to drive but still get decent mileage. Just like everybody else, we don’t have a lot of money – I’d like to do a crate engine but that would eat up most of our budget for the rest of the truck. Any suggestions?

R.J.

Jeff Smith: We’re never at a loss for suggestions. Yes, the easiest thing would be to just click on Ford Racing crate engines in the Summit Racing catalog and pick out a nice engine. Your truck’s engine compartment is wide enough that a mod engine like the Dual Over Head Cam (DOHC) Ford Performance 5.0L Coyote engine with 435 horsepower would be a great fit. The attraction is this is a brand new engine with a great warranty that would probably knock down 20 mpg with a good automatic overdrive and offer outstanding drivability. The price is also attractive at a very reasonable $6,935 from Summit Racing.

While attractive, there’s a reason that price seems low. It’s because you will need a list of parts that begins to get expensive with a computer, wiring harness, a pile of sensors, exhaust, and a good EFI style fuel delivery system. And these are just the main points. There will be dozens of custom requirements, including a different oil pan.

Of course, you could still do this by choosing a used, late model SOHC mod engine like out of a Crown Vic as an alternative. The smart move would be to retrieve the engine and trans together along with the accessory drive, computer, wiring harness, and all the sensors necessary to maintain the engine’s integrity. The down side to this adventure is again difficulties with the oil pan and headers. At this point, it might be better to just go ahead and use the Crown Vic front suspension as well which would dramatically update the handling, braking, and overall driving experience. While that’s a cool route, that’s high-level stuff that’s still expensive.

My guess from your letter is that this may be your first shot at car building. You didn’t mention your background so I’m going to assume that you have bought the truck and now are just trying to decide which way to go with the engine and perhaps the transmission.

In this case, I think that a simple swap to a 5.0L Windsor small block with a carburetor would be something that is relatively easy to accomplish and perhaps within your budget as well.

Ford’s 5.0L crate engine is a great idea and offers plenty of power with a 345-horsepower long block (PN M-6007-X302B) with 9.0:1 compression, aluminum GT-40 heads on a 4-bolt main block, and a hydraulic roller camshaft. This crate engine from Summit Racing will run $6,999, and my sense from your question is that this might be close to the entire budget for your truck. So let’s take a cue from this engine and see if we can build something pretty close for a lot less money.

We’ll concentrate here on just the engine. I did a story for a major magazine a few years ago that was a very similar approach with my buddy Tim Moore. During one of his monthly junkyard tours, he found a 2001 Mercury Mountaineer in the yard with a complete engine. The SUV looked in really good shape with around 120,000 miles on the odometer. We pulled the valve covers and the inside looked very clean, so the owner had properly maintained this engine. It seemed that the trans had died and the cost to rebuild it was probably more than the vehicle was worth. So it ended up in the junkyard.

We pulled the engine and brought it back to Tim’s shop. Tim bought the engine without the EFI intake, exhaust manifolds, or the accessory drive for roughly $400. This engine was rated at 215 horsepower and featured a hydraulic roller camshaft, 9.0:1 compression, and GT-40P iron cylinder heads. These heads are among Ford’s better flowing 5.0L cylinder heads and can make some decent power when modified slightly.

We modified the iron heads with some simple porting by Mike Slover at Slover’s Porting Service and the addition of a set of Manley exhaust valves to compensate for the stock exhaust rotators. The reason for this swap to the Manley valves is to relocate the retainer lock position on the valve to allow the proper valve springs to be used. Plus, Slover machined the heads to allow the use of a better valve spring to go with the stronger cam we planned on running.

Once the heads were done, we added a longer duration performance camshaft with 221/229 degrees of duration at 0.050 hydraulic roller cam and reused the original lifters, which is acceptable with roller cams. We then bolted on a set of headers, an Edelbrock Performer RPM dual plane intake, and a Holley 750 cfm carburetor. The engine made a solid 350 horsepower at 5,700 rpm and improved the torque as well.

Our recommendation for you would be a similar version with some minor changes. First, the cylinder head work will probably cost around $800 for the Manley valves, valve springs, retainers, studs, guideplates, and roughly $375 worth of machine work. If you wanted to add larger intake valves, new guides, and a new valve job, the price could easily run in excess of $1,000. At that point, you would be better served to consider a new set of aluminum heads that will flow significantly more than the stock GT40P.

The Ford GT40P is the best flowing of the production iron Ford small-block heads. But to add a performance cam requires significant mods by adding a Manley exhaust valve and machining to the valve guide to allow larger springs. Add in all the parts and labor and the price approaches the cost of a new set of aluminum heads.

We looked into affordable heads for the small block Ford and found that among the least expensive was a set of Trick Flow aluminum heads that is ready to bolt on. This is more money, but you also get a lighter, aluminum head that also improves compression a little bit with its smaller chamber.

We earlier mentioned the cam that we tested was around 221 degrees at 0.050-inch tappet lift with 0.549/0.565-inch lift. This isn’t a real aggressive camshaft and it still managed 16 inches of manifold vacuum at 900 rpm. You might be better served with a shorter duration cam for a mild 5.0L in a pickup, especially with an automatic that will probably run a stock or near-stock torque converter.

What few people recognize with cam selection is that with longer duration, the engine loses idle efficiency. Then when combined with a tight stock torque converter, it makes it difficult to tune the engine to idle properly with the transmission in Drive. Often, the carburetor must be tuned rich in order to keep the engine running.

For this reason, I’d suggest something more like a cam of around 212/218 degrees of duration at 0.050-inch with a valve lift of 0.512-inch. The COMP Xtreme Energy hydraulic roller cam, part number 35-349-8 is from the Summit Racing catalog and will allow you to use the original stock hydraulic roller lifters. With this much lift, you will need to perform the modifications to the stock GT40P heads if you decide to retain them.

As for an intake, we really like the Edelbrock Performer RPM dual plane. Don’t be fooled by suggestions that a single plane is a good street manifold. That single plane manifold design kills low-speed torque in favor of high rpm power but unfortunately unless you go with a bigger cam and better heads, it’s not a good combination. A 600 cfm carburetor from Edelbrock or Holley would be an excellent choice. There’s no power gain at this level to go with a 750 cfm carburetor.

With the stock GT40 P heads modified to accept this smaller cam, you can still expect to make around 275 horsepower with headers and perhaps slightly more. That’s a solid improvement of 50 horsepower over a stock engine with headers.

We’ve just given you the basics here as there are quite a few important details like ignition gear compatibility, timing recommendations, roller rockers as an option, and many more points. But these main recommendations will aim you in the right direction and help make that pickup run strong.

It’s worth the investment!