Mustang MonthlyHow To Tech Qa
1972 Ford Mustang Grande & 1965 Ford Mustang Fastback - Beyond The Basics
Vintage Mustang Tech Advice From Bob Aliberto
Brighter LightsI bought a '72 Mustang Grande last September and have begun working on it. I have a question about the gauge-cluster illumination. I replaced all the bulbs with the 194s specified in the manual, but it's still difficult to see the gauges in the dark. What can I do to improve visibility? I was thinking about whiteface gauges but I don't really like that look. Do you have any other suggestions?John SlaterVia e-mail
The '71-'73 Mustang dash illumination has always been the source of complaints and, as the cars aged, the situation became worse. Typically, the bulb shields inside the dash cluster, which provide the blue light, discolor, making the dash lights dim. Also, the back of the instrument bezel becomes dull over time, further aggravating the problem. Try replacing the bulb shields with a new set and painting the back of the bezel with a flat-white paint. The shields are available from Scott Drake Mustang Parts (3101 Camino Del Sol, Oxnard, CA 93030; www.scottdrake.net; 805/988-9992) in a variety of colors and the paint is a standard hardware-store item.
Leaky SealI own a '65 Mustang fastback. Last summer, I put in a new timing chain and water pump. Now I'm getting a fine mist of oil on the front of the engine. The fan is blowing it around and up onto the hood. We've checked the problem under a black light and found some oil coming out of the intake. I've changed the two gaskets on the intake, but the problem is still there. Do you have an idea of what's wrong and what I need to do to fix it?Les NortonWausau, WI
Although the black light seemed to show a leaky intake gasket, I don't believe this is the cause of your oil leak. The intake manifold was not disturbed during the timing-chain replacement and occurred only after the removal of the timing-case cover.
The leak is most likely from the front crankshaft oil seal inside the timing cover. If the seal leaks, oil will be thrown out by the spinning vibration damper where the fan picks it up and blows it around the engine bay. If the vibration-damper hub is not centered in the oil seal, the seal will leak. When installing the timing cover during chain replacement, it's quite possible the cover is installed off center, as the cover mounting bolt holes allow the cover to shift around. The cover must be centered before the mounting bolts are tightened. A common mistake is to tighten the oil-pan bolts that go into the cover before tightening the cover mounting bolts, as this will pull the cover down and off center.
Your situation will require the removal of the timing cover in order to replace the front seal. Avoid simply loosening the cover to try to shift it about, as the cover gasket may not reseal and an internal water leak may develop. The seal should be changed, as it's most likely worn in one spot and will continue to leak. When installing the cover, pay attention to concentricity between the crankshaft and oil seal, and do not tighten the cover mounting bolts until you're certain the cover is centered. Tighten the oil-pan bolts last and don't forget to lube the oil seal with grease or motor oil so it won't burn during a dry initial startup.
Going For GearsI currently own the car I've been looking for since I saw Steve McQueen flying around San Francisco in Bullitt. I found my Highland Green '68 GT with a 390 and four-speed last spring. It has seen little use since an engine rebuild in 1996. I am in the process of having the car completely refinished. It has a 3.00:1 9-inch rearend. I'd like to add a bit more jump off the line. Which gear would you recommend for my car? I was considering a 3.50:1. Some friends have suggested a 3.73 or even a 3.91 gear. The car is a factory A/C car, and I know the lowest gear from Ford in '68 was a 3.25 for factory A/C cars. If I do change the gears, should I go for broke and make it a Posi-traction? Please let me know which rearend configuration would be the best way to go.Dave TedescoHighland, IN
I agree, nothing adds to the performance of a vehicle more than a gear-ratio change. Depending upon the type of driving, I also prefer 3.50:1 gears for a street-driven vehicle. They yield plenty of torque for off-the-line performance yet allow decent highway driving as well. Anything numerically higher would make highway driving unpleasant, as the higher rpm would create unwanted interior noise and would kill fuel economy.
A limited-slip differential is not necessary for a street-driven car unless there's a need to tie both rear wheels together. Under most street conditions, both rear tires have an equal amount of traction, therefore even an "open" differential will apply equal torque to both rear wheels. However, if traction is limited or lost on one wheel, an open differential will send all the torque to that side, forcing that one tire to spin. A limited-slip would send torque to both rear wheels regardless of traction conditions. A drag-racing-style start will cause one tire to lift slightly, creating unequal traction to the rear wheels, thus a limited-slip differential would help in this situation. For ordinary street use, an "open diff" will suffice; but for drag racing, fast starts, or inclement weather, a Posi-traction type of differential is the answer.
Door Speaker PlacementI have a '70 hardtop, with a standard interior, that came with a few options like a C4 automatic transmission, a 302 2V, and A/C. I've been restoring it with the intent of keeping a stock appearance, but I've been upgrading it with some of the factory options like power disc brakes and center console. I picked up an original AM/FM stereo I would like to install with the standard speaker locations in the doors, but I'm not sure where the cutouts would go. I've searched the Internet, but have not found any help. Are there any templates available that show the proper hole locations?Perry ThuenteNaperville, IL
The speaker location is not super critical, therefore a template is not absolutely necessary. Basically, the speakers were mounted with their centers in line with the window cranks. A quick look at some photos and other Mustangs at a car show will give you the general idea. If your car has a deluxe interior, the back of the door panel may have an outlined area that's to be removed so it would be open to the speaker. It's important, however, to be certain the speaker will not interfere with either the window regulator mechanism or the glass. With the door panel removed, pick the spot where you feel the speaker should be, hold the speaker inside the door, and carefully operate the window to look for proper clearance. A small adjustment one way or another will not affect the overall look and may be necessary, as the dimensions of various speakers will vary. The speakers and grilles are available from most Mustang parts vendors and they can coach you on the correct size speaker.
Export BracingI'm planning to install an export brace in my '69 Mustang coupe and would like to know if it mounts below or above the mounting bracket on the firewall.Mark S. von WehrdenVia the Internet
The export brace mounts above the firewall flange and is a direct drop-in for your coupe. I highly recommend the addition of an export brace on a '69-'70 Mustang to strengthen the weak shock towers. These cars really respond to the additional support. If the brace does not fit between the shock towers, the towers have begun to move toward the center of the vehicle and must be spread out. This may require some muscle and may be accomplished with prybars between the export brace and shock tower. I usually remove the hood and jack up the car in the center, under the bolt-in crossmember, to allow the weight of the hanging suspension to help spread the towers. A stubborn vehicle may require the use of a hydraulic "Port-A-Power." Remember, the export brace is dimensionally correct, but the shock towers may require some "coaxing."
Block IDI've owned a '65 Mustang coupe for 22 years. I've picked up many parts over the years, including three 289 engines. One of the blocks has a C90E-6015-C casting number that I'm not sure belongs to a 289. I have some books with casting numbers, but I can't find it in them. The original engine is a C5AE-6015-E. My plan is to keep the C5AE stock and build up the C90E for a weekend swap. If you know anything about this, please let me know before I start to build this block.Keith MannVia e-mail
Your C90E block is a 302 casting. However, it's basically the same as any 289 block. You can rebuild it and use it as a replacement for the 289. A 302 is a stroked 289, so the internal parts, such as crankshaft and connecting rods, differ. Be certain not to mix these parts from one engine to the other. However, the cylinder blocks are completely interchangeable.
Send your questions to: Beyond the Basics, c/o Bob Aliberto, P.O. Box 205, Salt Point, NY 12578. E-mail us at email@example.com.