clearence

So, I am acquiring some GT40 heads from a buddy of mine. They have port work, bowl work, o-rings, decked .060 and have the correction cut on the intake side. I'm looking to see if I just use a standard 9333pt1 head gasket with o-ringed heads and if having GT40 heads milled .060 will I run into...

I have a 1990 GT and i was wondering how the fitment of 265/35/18 and 285/35/18 would work out and the exhaust pipe in the back is really close to the rear tire would i have to change the exhaust. And also would i be able to lower my car with these rims? They are the sve series 2 rims