the MII crosmember should be level front to back. and the upper A arm mounts sloped to the rear, usually 5 to 7 degrees. depending on front end weight, and how much the front springs compress and drop the front end during braking, Stock M II angles work good on most street rods. You might be able to make some spacers, lengthen the mounting slots to get the upper a arms high enough to clear your frame and have enough adjustability. with the springs removed you could move the suspension up and down to make sure you wouldn't be binding up your ball joints , strut rod, tie rods etc. Shelby moved the locations of the A Arm mounting points to get better handling on the 65 mustangs. but most street rods won't be road racing.