Does anyone make a a notching kit for the Maverick? Don't want to eliminate the upper control arm, just notch the tower for more room.
Not aware of a kit. How much room you need depends on your motor and heads. I would keep the notch to a minimum (just enough + ) in order to keep as much strength and integrity of the tower as possible.
I guess I'd take a different approach. If it were me I'd figure as long as I'm cutting into the shock towers I'd want to make as much room as possible and still clear the springs, then put every bit of reinforcement possible into that area to make it stronger than new. That means putting the Boss 302 Mustang reinforcements on the wheel side. https://secure.cougarpartscatalog.com/towerbrace.html And also the set of plates which wrap from the motor mount/suspension mount bits around the shock tower and down to the frame rails. https://www.stangfix.com/threads/shock-tower-reinforcement-day-2.8632/ I don't think any of this stuff is made as a drop in for a Maverick, but it wouldn't be that hard to make...and even the "kits" don't fit as is without significant prep and adjustment.
When I did mine I started 1/2" or so inboard of the bolt hole for the firewall brace and dropped straight down until about an inch above the upper control arm. Filled in the gaps with 3/16" steel plate.