Valve Adjustments

If you have adjustable lifters, the best method is the "9" method.

Number valves from front to back 1 through 8.

It is fairly easy to determine when a valve is at the top of it's lift. When you have reached that position on #1 valve you adjust the corresponding valve to equal "9". In this case it's #8 valve.

Continue with 2&7, 3&6, 4&5, 5&4, 6&3, 7&2 and finallly 8&1.

If you use different clearances for intake and exhaust, you need to pay attention. I put a piece of masking tape along the bottom of the ports and mark the settings there and cross them off as I finish.

First of all, forget about where the pistons are at. The tappets (push rod as Ford called them) must be adjusted with thin wrenches when they are on the peak of the cam lobe, and the clearance must be checked when they are on the heel (lowest point). Hand crank the engine a few times and watch the valve stems and you will see this.
Ideally, you would want to adjust the gap when the valve tappet was on the heel of the lobe and the gap could be measured with feelers. Unfortunately, the tappet adjustments are not accessible at that position, and the cam must be rotated and the tappet raised to make an adjustment. At that point the tappet can be adjusted, but the gap cannot be checked. Thus a lot of cranking is typically required.

Here's the trick:

Valves are numbered one through eight from front to back. For whichever valve tappet is on a cam lobe peak at a given instance, there is another valve tappet which is on its lobe's heel.
By knowing the relationship between the valves, (Rule Of Nine), you can do two things at once and adjust and measure multiple valves in steady progression (if you keep track of things). This will greatly minimize the amount of cranking and adjusting necessary.

The way the Rule Of Nine relationship works is like this: If for instance #6 valve is full open, then it can be adjusted with wrenches. Also at the same time the #3 valve tappet ("9" minus "6" equals "3") is on the heel of its cam lobe and its gap can be measured at the same time as #6 is being adjusted.
Now crank a little more until a different valve is full up, and adjust it and/or measure the gap on the other valve tappet whose sum equals "9" (e.g. if #2 is full up, then #7 can be measured, and #2 could also be adjusted if you know how much). Keep cranking until a different valve is up, and adjust it and measure the gap of the one whose sum equals "9".
Adjustable self-locking valve tappets have a 24 pitch bolt, which means that one revolution of the bolt equals changing the gap 0.042 inch. Since the bolt head has six wrench faces, it is fairly easy to estimate rotating the bolt 1/6 of a revolution, or one face, or 0.007 inch.
Furthermore, with a little eyeball engineering, you can guesstimate 1/3rd of a rev of a hex bolt wrench face with the two wrenches in your hand. This is ~0.002 inch of valve gap adjustment per wrench face.
With a little practice, you can measure and record the gap when the valve tappet is on its heel, and can adjust it to within 0.002 inch of where you want it the very first time that same valve is on its peak.
This can really minimize the amount of hand cranking necessary when the engine is in the car. If the engine is on a stand, then perhaps a lot of cranking is not such a big deal.
This procedure works very well on Model A cams, and pretty well on Model B cams, though B cams have a slightly different lobe separation angle and the 'down valve' is not as centered on the heel when the other valve is at its peak.

Recommended Tappet Clearance (inches)
Camshaft Design	Intake Valve Clearance (gap)	Exhaust Valve Clearance (gap)
Model A A-6250	0.015	0.015
Model B B-6250	0.015	0.022
Stipe IB330	0.012	0.012

The table above shows the recommended design push rod clearances (cold) for several cam profiles. A typical clearance setting of 0.013 intake and 0.015 exhaust is also commonly used by many people, and also used when the cam profile or the cam grinder's recommendation is unknown.
It is best to avoid setting the exhaust gap too small, as this can create insufficient heat transfer time of the valves on the seats and burn the exhaust valves. Linear expansion of a hot exhaust valve also decreases clearances at a higher rate compared to an intake valve.




Resources:  http://www.fordgarage.com/pages/ruleofnine.htm