Milling an aluminum intake........

For archive purposes

Chrysler LA engines:

Face Angle -3°

Intake Cut .0095”

so remove .0095” for each .010 removed from heads.

"Where the face angle rakes in (less than 45 from vertical when assembled on the motor), the angle is negative, such as Chrysler LA, etc. Remember: subtracting a negative number makes it a positive number!
Multiply the result of the calculation by the head gasket mill distance to get the amount to be taken off the intake flange surface for proper manifold alignment. In some motors (especially those with integral valley covers), additional compensation must be made for end seals, etc.
A positive example: RB (413, 440) face angle is 10° positive.
.707 ÷ SIN(35) = .707 ÷ .5736 = 1.2326, so remove .0123” for each .010”.
A negative example: LA (340, 360) face angle is 3° negative.
.707 ÷ SIN(48) = .707 ÷ .7431 = .9514, so remove .0095” for each .010”. " -http://victorylibrary.com/mopar/intake-mill-c.htm