I've owned this car for 3 years now, and have always been disappointed by the braking. I really like the stock wheels though.
Used 25mm H&R adapters.

 

Amazing, I would have bet they would not fit...and I would have lost.

 

Looks nice though.

 

I'm surprised those fit. If that's all it takes to fit the brembos under the stock wheels that makes it a lot easier and cheaper to do the swap. I really want better brakes on my car, but I can't do new wheels at the same time. Those are the track pack brakes, right?

 

Same brakes I have. Yes

 

By your pics, the front and rear look completely flushed with the fenders...is this correct? And I take it that there was plenty of lug bolt threads left to safely secure the lug nuts to the wheels? Looks good!!!

 

Yep they are flush when the suspension is static, however as the suspension articulates they do move in and out slightly.

I think you're thinking of spacers. These are adapters, they bolt onto the stock lugs, and then the wheels bolt onto them.

 

is there enough room to do this with 1/2" spacer instead of 1" adaptor? using ARP studs of course

 

I just measured, and there is exactly .5in at the closest point between the caliper and wheel. Since my 25mm spacers are just under an inch 1in = 25.4mm.

So theoretically they would clear by .4MM but that is just me doing my best with a measuring tape, so that is well within my margin for error.

Don't forget that there will be flex in the rim and the wheel bearing.

My f-body had a 1/4in gap between the spindle and rim when static. It was fine on the street, but on track the rim and tire flexed enough that they contacted the spindle.

Same thing happend to my buddy, had about 1mm of clearance between his wheel and caliper. It seemed fine, but after driving it around he found the wheel had marks where the wheel was hitting the caliper.

 

I believe people have done it with a 1/4" spacer (roughly 5mm). The stock Brembo wheels only clear by about 1/4" anyways, so I am 95% certain the 18s would clear with a 1/4" spacer. If not, 5/16" then.

Pick up a set off amazon and find a local guy who will let you try your wheel on!

 

I'm 100% sure you are wrong at least for my wheels.

I've got the unused 1/4in spacers in my garage to prove it. They weren't enough to even get the wheel on the car, much less drive it.

Each wheel design has different spoke clearance, and the only way to be sure is to try, but 1/4 wont get you anything with the 18in bullit 5 spokes.

 

Well, wasn't sure. I was just going off memory. Just saw your original post said you used 25mm, basically 1". Didn't think they needed that much clearance for the stock 18s. Fricken Ford and their super high offset stock wheels!

 

Thanks for the info! I was hoping to fit the factory rims w/ brembos since I have near new tires.

I've run 1/2" spacers on track cars for many years in the past (w/ ARPs). I'd feel plenty comfortable doing the same on the street. I don't think I want to do much more than that nor feel like dealing with adapters now.

I have the same stockers and Phoenix, and with the 1" adapters the car looks great.