Using a dial indicator and a magnetic base on the flywheel, set the dial indicator to 0 at the top of the hole and then slowly turn the engine over (with the plugs out) by hand-stopping every 90 degrees to indicate the runout on the dial. Also write on the bellhousing which way the hole is off by using arrows. This will help you figure out which way to move the bellhousing and by how much.
Shift Alignment
Butch 460, via CarCraft.com: I have a '69 Mustang with a transplanted 429 and a Ford Top Loader four-speed transmission. To make the Top Loader work with headers, I used a bellhousing from a mid-'90s truck with a hydraulic-clutch setup. I installed a new clutch slave and master along with a new performance street-and-strip clutch and pressure plate. My shifter is a Hurst Super Shifter and I have had a Hurst inline V-gate with the same results. The problem I have is that at above 5,500 rpm, the trans will not shift into the next gear. The 1-2 shifts are the worst, the 2-3 shifts are better, and 3-4 shifts are OK. Below 5,000, the trans shifts fine but it is not smooth, as in a single motion; you can feel it come out of First into Neutral and then feel it go from Neutral into Second. My shift rpm is 6,200 just as when I had the automatic in it, but at this rpm, it is impossible to get it to go into gear. At lower engine speeds it shifts OK without grinding or popping out of gear. Any idea what is wrong? Is this common for stock Top Loaders to not work at higher rpm? Are hydraulic clutches noted to be slow to disengage? Would a needle pilot bearing help? I would gladly add special internal parts to the Top Loader if only I knew which parts and if this is the problem
Jeff Smith: Butch posted this question on CarCraft.com under the technical forums, and several readers responded with helpful suggestions. We agree with the respondents who mentioned bellhousing alignment. When the large input-shaft opening in the bellhousing is not aligned properly with the crankshaft centerline, high-rpm shift difficulties do occur. What's strange is that these problems are usually the worst when attempting to shift into Fourth gear, because that is when the transmission connects the input shaft with the output shaft. This is when the misalignment causes the most grief.
Regardless of the gear change when the problem occurs, the fix is not all that difficult. The idea is to use a small dial indicator to measure the eccentricity or horizontal centerline runout of the bellhousing. The spec is no more than 0.005 inch. The fix is to use offset bellhousing dowel-pin bushings to move the bellhousing in relation to the crankshaft centerline until the runout spec is achieved. The Lakewood pins you need are Ford style at 0.500 inch in diameter. They come in three offsets: 0.007 (PN 15950), 0.014 (PN 15960), and 0.021 inch (PN 15970). We've found that most problems can be handled with either the 0.007- or 0.014-inch bushings, since the amount the bellhousing is offset can be doubled. In other words, if the bellhousing is off by 0.010 inch, then the 0.007-inch offset will be more than enough, since it can handle up to a 0.014-inch offset. The idea is to move both bushings so that they offset in the same direction, otherwise you won't be able to slip the bellhousing over the dowel pins because they will be independently offset.
A roller pilot bearing really doesn't do much for the performance of the transmission except that its clearances are a little tighter than a bushing and may be better at keeping the input shaft in-line. But you must align the bellhousing in order to take advantage of what the pilot bearing offers. We'd also suggest spending an hour or so carefully setting up the arms on the transmission between the shifter and the trans. Time spent ensuring that these arms are adjusted properly pays off with a cleaner shift. One way to tell if the adjustment is close is when the shifter neutral gate offers a clean path as you push the stick back-and-forth sideways. If the shifter hangs up on the 1-2 or 3-4 gates, then the arms are not adjusted properly. We like to use a thin (about 0.020 inch) 31/48-inch-id AN washer between the shifter pad on the trans and the arm where it goes through the pad. This tightens up the rods and makes the shifter feel more precise. This should cure your shifting problems.
More Info
Lakewood/Mr. Gasket Co.; Cleveland, OH; 216/688-8300; mrgasket.com
Holley Makeover
Bill Willis, Bellflower, CA: I have a GM Performance Parts 350ci, 385hp Fast Burn crate motor in my '56 Chevy. The engine came with a 750-cfm Holley, and I was thinking of changing to a Rochester Quadrajet. Do you thing I am wasting my money, or should I give my Holley a little more TLC? Right now I get about 8 mpg in city driving and I think it can do better
Jeff Smith: Right off, Bill, I will confess to being a big Q-jet fan. I've spent months fine-tuning the idle circuit on several Q-jets and had them running beautifully. This is not to say that the Holley cannot be tuned to be more efficient, because it can. You just have to know where to put your efforts. Let's go over some details that will work with your Holley to improve your part-throttle efficiency. These same ideas will apply to any carburetor.
In terms of street operation, what most enthusiasts don't realize is that when you are cruising down the street or even motoring down the freeway at 3,000 rpm, all carburetors are functioning almost exclusively on the idle circuit. Any acceleration or heavy right-foot action engages the main metering circuit. While you are cruising, the throttle blades on both the Holley and the Q-jet have what is called the transition circuit, a small slot placed just above the idle stop position of the primary throttle blades. This slot introduces more fuel from the idle circuit into the engine. Eventually, if the throttle blades are opened farther, the blades will move past the end of the slot. It is near this point that the main metering system will begin to flow fuel out of the primary boosters. This means that any serious attempt to improve fuel mileage must address the amount of fuel delivered by the idle circuit. You'll have to go into the idle circuit of the carb in order to accomplish this task. It's not as simple as merely leaning out the idle-mixture screws.