Lowering springs will increase camber. You can get crash bolts (camber bolts) or camber plates if you feel the need to adjust the front. The rear camber is adjustable but a pain to do.
Do it yourself is the best way, cost me $35 for 10 qts of Pennzoil Ultra Premium full synthetic and a Motorcraft filter, anywhere else is going to cost $$$....
p.s. might want to describe where about in MA you are looking.
I would recommend that you check the 'feel' of manually moving the valves and see if there is a difference from side to side. Inspect all the connectors for corrosion too. Easy & free to check all of this and I doubt that you will cause further problems by doing the swap.
Double check the fuse and while you are there make sure the relay is good/seated properly to. It is located at the fuse box. Maybe check the pins in your connectors closely to make sure one didn't get bent...
I'm of the belief the last thing to do on a front heavy car like Mustang is put a narrow wheel up front unless you love understeer. Go for a 10" square setup in either of the two rear size tires mentioned for improved looks and performance. Be mindful of offset no matter what choice you make!
Within but that should not matter as per the TSB it covers aluminum panels back to MY 2000. I had printed out TSB in hand for my initial visit (ready for push back) and I would recommend you do the same with yours. If they refuse contact Ford directly.
I went to my local dealer when mine got the dreaded bubbles on the hood. They never even looked at it, just scheduled a time to have it replaced at a local body shop and gave me a loaner. I hadn't even bought the car there and did not have to bring up the TSB.
I'm guessing they don't sell a lot, that's why the price is so low. I traveled by back in the winter and am pretty sure it was almost the same price as regular then ($3.25/gl).
Current prices in Hudson, NY. Coincidently this is the closest E85 source to where I live... over 40 minutes away. The rest would take hours to get to....
When it comes to electric prices I pay no bother, I have solar and it covers all of my heating, cooling, and electric needs. Best investment...