REBUILD OR REPLACE?

I currently own a ’74 Barracuda with a 318. My car is equipped with an automatic transmission, and has seen continuous use since new. Over the years, the car has racked up an incredible 192,000 miles. I’ve had the car serviced regularly, and have to say that though this is a car that many consider a toy rather than daily transportation, it ranks as the most reliable vehicle I’ve ever owned. Though my car has very high mileage I have no intention of replacing it with a more modern vehicle, but would rather just keep it and drive it for years to come.

This brings me to my question. I consider 200,000 miles a milestone, and decided many miles ago that if my Plymouth reaches that number, I’d replace the engine. Here is my question. Should the original engine be rebuilt, or should I acquire a replacement from one of the remanufacturing outfits? I have looked at both options, and actually replacing the engine seems like it would be no more expensive than rebuilding the current engine. I have heard from some that the 318 is a little underpowered for the E-Body, and I should replace the engine with a 360. I like the idea of a remanufactured engine with a warrantee, and am not opposed to a larger, more powerful engine, although it would be nice to keep my car “numbers matching.” On the other hand, I acknowledge that my 318 car is not a true high performance muscle car, and as far as resale value, retaining the original engine may not be much of a selling point compared to the more popular 360. I’m tied in with a local engine shop with quite bit of expertise in Mopar engines, including high performance and racing engines, so I’d be sure of getting a competent rebuild. What do you suggest?

Fred Moore
Pasadena, CA
Via moparmuscle.com

Fred, this decision comes down to the level of competence and execution of the shop doing the engine work. The 318 can be rebuilt to better than new, but rebuilding one is not a job I’d leave to just any shop. A replacement engine assembly can be an unknown commodity, and the quality can vary considerably. If it were my decision and my car, I’d rebuild, though with the exception of machining, I’d do the job myself. If you know an engine shop that has expertise with Mopar engines, rebuilding the factory 318 is a very viable option, with the major advantage being that the engine can be rebuilt to better than new, and likely better than a remanufactured 360. In a custom build the engine can benefit from high quality aftermarket parts.

Improvements can be items to enhance the strength the engine assembly, such as by utilizing aftermarket forged pistons in place of the factory cast pieces. Performance enhancements can also be part of the engine program, depending upon the goals, with potential upgrades running the gambit from hotter cams, to custom ported or aftermarket heads, to improved valvetrain components, or even a stroker rotating assembly. The 318 can be built as you choose from dead stock to seriously wild, depending upon your goals. Although the notion of “numbers matching” isn’t a major issue with a 318-powered vehicle, I like the idea of retaining the original engine.


THE “X” FACTOR

I have a ’69 Dart convertible with a 340 engine, and four speed 833 transmission. I have to say that the car attracts attention anywhere I go. The engine is mostly stock, with some of the basic mods like a new dual exhaust system, and an Edelbrock AVS carb. I was considering reworking the exhaust with an X-pipe crossover system. I have heard a couple of small block street/strip Mopars at the dragstrip with these systems, and just love the high-tech sound. My local exhaust fabrication shop can create a custom mandrel-bent system, with an engineered X-pipe. Will that give my Dart the racy sound that impressed me so much at the track?

Chris Jones
New York, NY
Via email

Chris, you are asking a subjective question that is pretty hard to peg, but I’ll try. An “X” crossover definitely changes the way the exhaust pulses through the system, and has a unique sound that many enthusiasts really like. In addition, when properly designed, you can see a gain of about 10 lb-ft of torque, and even some top-end power. Actually, many of the “H” crossover arrangements I have seen are sketchy at best, since the ample looking pipe connection between the two banks often conceals a very undersized hole under the welded connection. The arrangement does not actually allow much flow for the exhaust to crossover.

Now the tricky part is whether it will make your Dart sound like the cars you admired at the track. To this, I’ll have to answer that it depends upon the level of modification of the vehicle in question. Some track cars carry pretty serious hardware, and that hardware can really unleash the beast at high rpm. You may well have heard a built small block pulling sweet tunes at 7,000-plus rpm. Don’t expect exactly the same thing with a relatively stock engine at 6,000 rpm. Taking into account the camshaft, induction, and compression ratio, as well as the header type, all of these factors and more will affect the sound quality of the engine. That said, a good “X-pipe” system can sound great even on a relatively mild engine.


HOMELY HEADERS

I work as a parts-puller at a small wrecking yard. One of the great things about my job is that I get the run of the place for the good stuff. None of the other yard guys are really into cars like I am, not even the owner. I got my car from the yard, and it makes this job worth it. It’s a ’68 Coronet with a 383 in it. It’s rough and rusty, but I put a 440 in it that I got from a Chrysler. I got a set of headers, a Holley carburetor, and a Torker intake. The headers are rusty and look bad. I don’t want to buy new ones. How do I make these headers look good? I want them to look brand new. I’m fixing this car up on the cheap. What should I do to the headers without spending a lot?

Brian Guilly
Via moparmuscle.com

If you really want them to shine and stay looking good you’ll have to have them metallic-ceramic coated. Pro coating isn’t cheap, but you can do this yourself at a moderate cost, if you have an oven big enough to cure the coating. I doubt the local pizza shop will work with you on this, so you may be out of luck here as well.

The least expensive alternative is to blast the headers and shoot them with good header paint. The blasting is the key here, and you can probably have it done commercially at a reasonable price. If you have access to blasting equipment, you can do it yourself and save. After blasting, hang the headers and spray them down with brake cleaning solvent to remove any surface residue, and they are ready to paint. Use a name brand header paint; black and silver last the best. Spray the paint on only thick enough to give complete coverage, and no thicker. A thick layer of paint will burn and flake off, while a thinner layer can last for years. Header paint cures from the heat of running the engine. Fire the engine and leave it on only long enough for the headers to start smoking and shut down to let the headers cool. Repeat this process a number of times, letting it run longer each time.