I had my strut towers notched for additional clearance but it’s still tight. My mechanic is going to modify one tube for the needed clearance.
If they're long tubes like my Hooker 6901's I find it easier to have the motor mounts unbolted and motor jacked up so I can move it from side-to-side a little bit. Move it towards the passenger side and install the driver's side first from underneath. That way the steering box doesn't get in the way. Then push the motor towards the driver's side and install the passenger side header. Bolt down the motor.
My shock towers are notched, too, but that doesn't help with header clearance. The headers sit lower than that. The notches along with modified braces definitely help with changing spark plugs, though.
When jacking up the motor make sure to put a block between oil pan and jack so you do not dent it . I have been lucky with the three sets that I have installed and only unbolted the drivers side. Car has to have the front jacked way up on bolt sides and on jack stands for safety to be able to turn the header enough to get it to go in. I always take the spark plugs out so they are not an issue
