inches x 25.4 = mm
mm x .03937 = inches

cubic inches x 16.387 = cubic centimeters
cubic centimeters x .061 = cubic inches
liters x 61.025 = cubic inches

1 da (N•m) = 7.373 foot pounds
foot pounds x 12 = inch pounds
foot pounds x 1.355 = newton meters (N•m)
foot pounds x .1383 = kilograms/meter (Kg/m)

cubic feet x 7.481 = gallons
liter x .2642 = gallons
gallon x 3.785 = liters

gram x .03527 = ounces
gram x .0022 = pounds
Kg x 2.1 = pounds

psi x 6.895 = kilopascals (kPa)
kilopascals (kPa) x .145 = psi
psi x .069 = bars
bars x 14.5 = psi

mph x 1.609 = kilometers/hour (km/h)

horsepower (hp) x .746 = kilowatts (kw)
kilowatts (kw) x 1.3405 = horsepower (hp)

(degrees Fahrenheit -32°) x .555 = degrees Celsius
(degrees Celsius x 1.8) + 32° = degrees Fahrenheit

Surface feet/minute = 3.1416 x diameter x rpm

Displacement
stroke x (1/2 bore)2 x 3.1416 x (# of cylinders)
= displacement or:
8 cylinder: 6.283 x stroke x bore x bore = displacement
6 cylinder: 4.712 x stroke x bore x bore = displacement
4 cylinder: 3.1416 x stroke x bore x bore = displacement

After machining the head at surface A, material should be machined from surface B for proper intake manifold alignment. Note how the bolt holes in the intake manifold do not line up after machining the head gasket surface A

The amount of corrective machining required varies with the angle at which the head is made. Head angle is the variance from 90°. For instance, a head that has the head gasket and the intake manifold surface made at a right angle (90°) to each other would be classified as a 0° head.

           10°  Head Angle (Small Block Chevy and Ford)
                  Amount Removed at "A" x 1.7 = Amount to be removed at "C".