I had to grind on the mounting flanges, but not on the bottom of the intake. You'll need to do a dry fit to see where you'll need to grind. I would advise eliminating the bolts and use studs instead. Also, take the 2 alignment dowells at the ends of the heads out and replace them with studs as well. That will hepl with aligning the exhaust and gets a bit more clamping force on them as well. You may also consider eliminating the factory mounting clamps, as they do not work very well with this mainifold combintions. I ended up making my own from 1/4" stainless after fighting leaks. I'll try to get some good pix of my setup posted tomorrow.
