Best shops for Mustangs in KC

I would like a list of Known good shops that know mustangs in the greater Kc area. I will be looking to do some more mods to my car this next income tax time and need to know of some good reputable shops in the area.

I had a place called Yancy's put a set of heads and 4:10 gears in my car a couple of years ago and they did a bad job on the gears and think they may have stuck the wrong oil dipstick in my car. It has a yellow handle and after an oil change it reads way high after just 5 qts. Jerks!!

KC-mustangs.com,,,,, I tried to register and am showing as a new member but it wont let me log in and I never got the confirmation e-mail.

I need the tranny tailshaft bushing replaced and a new rear main seal as it is leaking a little from the vibration from the bad bushing. I get vibration mostly felt in 5th gear around 2,000 rpm.
I also have some back firing issues when the car is started cold. It doesnt backfire at idle just when giving it gas when driving. Once the engine is warmed up a little it stops backfiring. I have new plugs and dist cap and rotor. The plug wires are good. I replaced the Coolant senser and adj the timing a bit higher and adj the fuel pressure and that seemed to help some. I retightened the intake and that helped a bit too. I recently added a bit more fuel pressure and that seemed to make it bit worse. Vacumn leak maybe? Sticking valve?
What ya think?