June 1, 2005

What's The Bore?In the Nov. '04 issue, the In Search of Mustangs column indicates that a 289 engine bored .040 should be considered a "throwaway" when rebuilding. What is the maximum bore you recommend?Birl AdamsWhitefish, MT

Engine-block castings do not have to be absolutely identical to each other, because precise areas will be machined to perfection after the casting is complete. A good casting is one that allows for the original machining without regard for future machining operations. Ford small-block engines have enough material in the cylinder-bore area to allow for a finished cylinder diameter of up to 4.030 inches and still provide enough material for proper cylinder-wall strength. This is common to any typical block casting from the Ford foundry. Some castings may have come out better than others and will have a more uniform, thicker cylinder-wall area that allows for an additional overbore, up to .060 inch in some cases. Simply stated, all small-blocks can be safely bored .030, while some can tolerate up to .060.

To determine a cylinder wall's thickness, the engine builder or machine shop can perform a sonic test. Should the block prove to be exceptional with thick, round walls, an .040 or .060 bore is OK. Sonic testing is expensive and not all machine shops have the equipment to perform the test. It's much simpler to use any block and limit the overbore to .030.

Power AlignmentI have installed power steering in my '69 Mach 1. The water-pump hose is on the left side, but my power-steering bracket might be for a right-side water pump. The bracket is a little off. Is there a difference between righthand and lefthand brackets?Gary MakarVia the Internet

The brackets do indeed differ slightly and can lead to alignment problems. As you mention, the problem is relatively small. With a bit of filing and a few spacers, the power-steering pump can be properly aligned.

Head SwapI have a '67 Mustang fastback with the 289 two-barrel engine. I recently upgraded to a four-barrel Edelbrock intake and carburetor, and recently got my hands on a set of stock heads from an '89 5.0 engine. Would it be worthwhile to install these heads? I also obtained a set of 1.7 rocker arms.Larry WaughColorado Springs, CO

Because the late-model 5.0 heads are basically a copy of the 289 heads currently on your engine, there is no advantage if you install them. The roller rockers, however, increase the camshaft parameters, but not as much as they would with a 5.0 camshaft. I suggest you switch to the Edelbrock camshaft that's designed to complement the carb/manifold combination. The Edelbrock folks have spent countless hours on the dyno to develop these packages, and they make good power without sacrificing driveability. A good performance exhaust system is also in order, utilizing headers as your budget permits.

Six-Cylinder DiscsAs a new subscriber, I don't know if you've answered this before. I've owned a six-cylinder '66 convertible for nine years. I rebuilt and installed a 351 Windsor, FMX transmission, and a 9-inch rearend out of a '69 Cougar. My only problem is the factory four-lug six-cylinder brakes on the front. All of the disc-brake kits do not bolt to the six-cylinder spindles. What's my best option to get better braking and possibly a dual master cylinder for safety?Dan BaberBuchanan, MI

You'll have to install V-8-style spindles in order to install disc brakes on an early six-cylinder car. Replacement of the small spindles is a good idea regardless of brake choice because the six-cylinder spindles are prone to breakage. They also utilize undersized wheel bearings that are prone to failure.

We have indeed covered this subject many times before, but we'll hit the highlights again. The V-8 spindles from most Ford intermediate vehicles are interchangeable as long as they are used with the corresponding wheel bearings and outer tie-rod ends. Two styles of disc brake assemblies can be used: either the four-piston, fixed-caliper style from 1965-1967 or the single-piston, floating-caliper style from 1968 and later. Early fixed calipers utilize a bracket to mount the caliper to the spindle, therefore the spindle can be from either a disc-brake or drum-brake vehicle. Later floating calipers fasten to the spindle directly, thus disc-brake spindles are unique to a disc-brake car.

Your choice of disc-brake styles will obviously dictate the spindle choice. The early four-piston setup is correct for your car. However, they cost more and used parts are not readily available. The newer style single-piston setup is more common as it was also used into the '80s on Granadas, so a donor car can usually be located fairly easily. If you still have the '69 Cougar, its brakes will bolt into your convertible with the '69 tie-rod ends.

A dual master cylinder from a '67 and newer Mustang will fit your early car with a bit of fabricated plumbing. A proportioning valve for the rear brakes must also be plumbed in.

Boss Headers In A '66I have a '66 Shelby GT350 with a Boss 302 engine and I'm trying to locate someone who makes headers for that application. Any help would be appreciated.Brad PippettVia the Internet

A set of headers for a '69-'70 Boss 302 Mustang will fit your combination. However, the tube for the No. 2 cylinder will require some slight modification because the tube interferes with the shock tower. It should be cut and rewelded to provide clearance.

Another choice is a set of specialty headers designed to install a 351 Cleveland engine into a '65-'66 chassis. As you know, Boss 302 heads are almost identical to 351 Cleveland four-barrel heads, so those headers will bolt up to the Boss engine. A small interference may occur because the Cleveland is a little taller and wider than a Boss 302. However, it can be done. Call Mustangs Unlimited at 888/398-9898 for a set of its conversion headers.

Not-So-Cool JerkI own a '72 Mustang hardtop with a 302/automatic. For some time while driving between 25 and 55 mph, I get a jerking, holding-back sensation. I performed a complete tune-up (points, condenser, cap, rotor, plug wires, PCV valve, and air filter) and even switched to a PerTronix ignition system. The problem is still there. The car accelerates just great, and runs fine otherwise. It only exhibits the problem at a steady speed. What else should I check?Andy KobackVia the Internet

The condition you describe is a classic case of "lean surge" and is related to a problem in the carburetor. The problem is in the intermediate circuit and is creating an improper air/fuel mixture under light throttle conditions. A carburetor is a combination of idle circuit, intermediate circuit, and power circuit as it must provide the correct air/fuel mixture under all those driving conditions. As you can imagine, the carburetor must blend the circuits together continuously, depending upon engine load, for seamless operation. It doesn't take much to upset the carb and only a small amount of debris or varnish deposit from old gasoline can partially clog a circuit. Rebuild or replace your carburetor and your problem should be solved.

Sprint StripingI purchased a '66 Mustang hardtop in 2003 and began the long process of converting it into a restomod. The pinstripes on the side puzzle me. I searched many Web sites for accent-stripe kits, but can only find the ones for a GT or a Shelby, which my car is not. Then, in your June '04 issue, there was a Resto Roundup answer that said the Sprint 200 edition included a "body-side accent stripe." My car came with the chrome air cleaner with the Sprint 200 decal, so that explains the striping on my car. My question is, where can I get replacement stripes?Jennifer CookNew Bern, NC

The accent stripe is unique because it was painted on at the factory, as opposed to an added-on tape stripe. A special fixture was used on the assembly line to apply the painted striping.

As such, the stripes aren't reproduced. However, you can use striping tape, available in various width and colors from any local autobody supply store. A shop that specializes in vehicle lettering can easily hand-paint the stripes should you prefer the factory look as opposed to aftermarket tape.

Send your questions to: Beyond the Basics, c/o Bob Aliberto, P.O. Box 205, Salt Point, NY 12578. E-mail us at mustang.monthly@primedia.com.