Jeep 4.0 in 69 Barracuda

I have found 6 inch starters, but I have 5.5inches of clearence before hitting the idler arm. So I am thinking no longer than 5 inches from the mounting surface is my target.

Now with gear reduction starters, if it sits up high enough to be above the idler joint, that would allow for more length. Keep in mind, the 73 v8 center link bolts from underneth the idler arm. I think there is a picture on prior page showing this.