We drove the car around the block and discovered that the 255-70r15's contacted the wheel well on both the driver's and passenger side. This is with air shocks pumped to 100 psi. The approx. 1/2" difference between the two sides is there, but the 29.1" OD is too much.
We returned the tires to the dealer and had him mount 255-60r15's. These are 27" OD and, in spite of more than 9" tread on the ground, clear everything by at least 1".
We don't like losing the OD with the 4.11 gearing. This combination puts us at 68.4 mph at 3500 rpm. It's OK, but not ideal for freeway cruising. We are not going to do anything about the axle offset at this time. Depending on how the ratio works out, we may end up with a different rear end--maybe 9" Ford with gearing in the low 3's. With the power of this engine combo, this 8.5" unit may not survive very long. Will keep you posted on that.
The surprising thing with these tires is that the dealer took the tires back for full credit and only charged for mounting and balancing. This in spite of the fact that we bought the tires in March. The dealer is Baumgardt Tire in Appleton, Wisconsin. The owner is a Pontiac nut, which may be why this worked out.
We mounted and aligned the hood. The rear corners of the hood were too high, which was panic time until we remembered that shimming the front bolts that attach the hood to the hinges lowers the rear of the hood. After a few hours of jockeying the front fender mounts, core support, and hinges, the hood alignment is good. We will have to remove the hood one more time to cut the passenger side hood bracing to fit the Ram Air pan.
Front bumper will be the last step of assembly for this project. It's assembled and ready to mount.