I just went out and actually measured and I have 3 and a quarter inches of space above the front tire and a tad under 3 in the rear. Is this normal for 255/45 tires?
The car should be between 26.5" to 27" tall at each fender. Ford quality control SUCKS! *Many* cars have 1/4' -1/2" difference between sides. Also, the difference in wheel load between the left and right can be ~15+%.
MM and Griggs. *So far*, I haven't seen a single bad product from either. *Most* (but not all) FRPP parts are also very good. But, the FRPP bumpsteer kit is a re-package and doesn't come close to the MM parts.
For a GT, *in general* there's ~1.5" to 2" of clearance between the tire and fender, The *GT* does NOT sit "high". The height of the GT is like that *for a reason*! Lowering a GT by ~1/2" is pretty safe. Beyond that, you have things to consider.
I lowered my t-bird by ~3/4" and I like it lowered. I went with the FRPP kit (they no longer make it). Still, during the winter, it sucked as a daily driver. Now, I drive a FWD car in the winter.
I'm now in my "what spring/combo" phase for my stang. I have over a dozen springs (do NOT ask, or I will vent and want to take out contracts to *KILL* people because of the PURE BS that used to be posted about springs!).
I've been doing Electrical and Mechanical engineering (Elec is my strength and bread and butter) for over a dozen years. So, I was super surprised when I went to get some spring info on my *20* year old car, and got tons of bogus info.
Many people don't have an idea on tolerances, or how important the *whole* package is. Add in the shorter k-frame and smaller fender opening on my '86, and it's been a nightmare! So, over the winter, I got over a dozen books, plenty of springs, talked with some manufactures through work (I do some ME stuff) and worked through the BS posted again and again in the forums.
Remember:
Most people are trying to help!!! But, without engineering experience, it's hard tell between "what's luck" and "this will always" work.
So, like with the EEC, I'm taking the experience of MANY others and the HELP and information from MANY others and shorting out what's luck, good idea, bogus info. In reality, I'm mainly checking facts and information. The MANY other people on the forums are providing the core information! Then, I add in science, math, engineering, and
hopefully result in some reliable information.