Mump 0911 27  Restored 1966 Mustang Convertible Rear View
Bob Aliberto
December 18, 2012

Vent Adjustment

I am having a hard time adjusting the right-side vent window on my '66 Mustang convertible. The top of the window needs to be adjusted outward about 5/16 of an inch. I understand how the adjustment process works, however I cannot get the window to tip out at the top. The bottom adjusting stud on the window track is loose, and I have loosened the bolts that secure the window frame and screwed the upper adjusting stud. I then tightened the lock nut, but the window will not move. It seems the vent window frame is tight against the bracket with the mounting bolts in it, so it does not have any room to move. I have tightened the upper adjusting stud all the way in and tried to pull the bottom of the vent window in towards me by tightening the lock nut, but I believe that I am only bending the vent window frame. This would not be a problem except when I adjust the rear quarter window, it presses too hard into the convertible top weather seal and cannot be rolled all the way up. I am wondering if I can remove the vent window frame and spread the slot that it fits into a little wider.

Paul Kogler
Via the Internet

The vent window adjustment can be troublesome and requires patience for sure. The window frame is hard to move when the two through bolts that secure the bolts to the upper door are tightened. These bolts squeeze two flanges that are an integral part of the door around the vent window frame. Sometimes the flange will not allow the vent window frame to move freely. Try loosening the mounting bolts and other adjustment screws, then rock the vent window frame in and out to spread flanges.

Slide the frame forward so that it contacts the roof pillar weather-strip evenly, then loosely tighten the bolts, hold the frame in or out to its approximate correct position, and turn the adjustment studs until they hold the frame in this position. Snug the mounting bolts once the adjustment is completed.

The rear of the window can be adjusted by moving the rear window track. This may be necessary to correct your quarter window to front glass seal. The adjustment bolts are on the door jamb underneath the removable metal plugs.

The quarter windows are also adjustable when the interior trim panel and rear seat are removed. The quarter window can be moved in almost any direction, and will allow for the convertible top weatherstrip to quarter window glass seal to be corrected. The factory shop manual is an excellent reference for glass adjustment.

Swap Linkage

My 15-year-old son and I are buying a '67 Mustang hardtop with the six-cylinder engine. What clutch linkage changes are needed if we swap to a small-block V-8?

Trip Banks
Lake Forest, IL

The '67 six-cylinder and V-8 clutch linkage is basically identical except for the equalizer bar and lower adjustment rod. The frame rail and engine block pivots, as well as the rod from the clutch pedal to the equalizer bar, are the same and can be reused. The '67-'70 small-block V-8 equalizer bar and adjustment rod have been reproduced so they can be ordered from your favorite Mustang vendor.

Need Better Braking

I have a '66 Mustang that I recently purchased as a daily driver. The brake pedal feels too hard when pushing it. The car stops straight and true but lacks stopping power (panic braking causes me to panic!). It has 4-wheel disc brakes from SSBC, power brake booster, dual master cylinder, and proportioning valve. The brake fluid has been completely flushed and the brake system bled. The 289 engine has an aggressive cam and only pulls 10-12 psi of vacuum at idle. I'm considering two options: 1) Remove the power brake booster or 2) install an electric vacuum pump. I'm sure option 2 will offer more braking power but will removing the power booster offer an improvement over what I have now?

Michael Taylor
Murfreesboro, TN

I often find that the friction material used on some brake pads is simply ineffective and provides little stopping power. Your Mustang should stop, or at least lock up the brakes, regardless of the power assistance. Power brakes add to the enjoyment and ease of operation but do not add much braking efficiency.

I'd get the car to stop well first, then troubleshoot the power assist issue later. An electric pump may be necessary for the booster to work with only 10-12 psi of vacuum. However, you may find that power assist is not necessary at all.

Call the vendor to see if they offer another brake pad compound, similar to semi-metallic performance pads. Look for an aggressive street pad but avoid expensive "racing only" pads as they need to be hot to work efficiently. You will find that the brake pad material has a huge effect on braking performance.

Smaller Fuel Neck

I own a '66 Mustang hardtop with the 200 cubic-inch six-cylinder. I would like to know if there is a smaller gas filler neck for early Mustangs to fit unleaded pump nozzles. Hopefully, a smaller opening will prevent fuel spills.

Dennis Saylor
Eagle Creek, OR

I am not aware of a gas filler neck that will prevent fuel spills. The design of the tank with a very short filler neck makes filling the tank difficult without spilling. This is a very common complaint among early Mustang owners and simply a part of ownership.

I fill the tank slowly and listen for the sound to change as it fills, backing off on the fuel flow as it nears the top. Just like fueling a motorcycle, proceed slowly and be prepared to mop up a few drops when done.

Let us hear from you. Send your '65-'73 Mustang questions to:
Beyond Basics, c/o Bob Aliberto, P.O. Box 205, Salt Point, NY 12578. Send email to