Ive started a topic called " mustang 2 front end angles" on that very topic... here is one of the replies:
OK guys, Here it is. I did this on my A coupe 14 years ago, no problems with alignment, ride or anything else. Your stock M-II crossmember has a factory setup of 11 degrees caster. Set your frame up at the desired ride height and level it side to side. locate the center line across the frame front crossmember and across the M-II crossmember. raise the M-II crossmenber up under the frame crossmember until it touches. The M-II crossmember will have to be level with the floor, front to rear and side to side. Check the measurement from a set point like the index holes in the upper spring saddles (just behind the upper shock holes) back the rear axel centerline on both sides. This should be right on. Tack weld the M-II to the frame whereever it touches. Now you have to cut filler plates and weld them in to close the gaps. Put the lower control arms on and clamp a piece of angle iron to the front edge of the crossmember so that the control arms sit level with the bottom of the crossmember. Install your strut rods and fabricate your strut brackets to the frame using the rods as your reference. The lower control arms must stay level. The geometry on these things only works if you don't mess with it. The wheel base on the M-II's are very close to Model A and B fords. The Front end will be aligned using stock M-II specs. Use the 4 cyl springs and cut one full wrap off. Don't know about the 32's but on a Model A the fenders won't clear the upper control arms. I modified the fenders with little relief fairings. I've seen some M-II's that were widened and the owners regretted it.