http://www.skytecair.com/cub_starters.htm

If your PA-12, PA-18, PA-20, PA-22 or even old PA-28 has an oil cooler in the front/center of the cowl (the "Cheesegrater up Front"), you have some options when it comes to selecting/installing a Sky-Tec starter in place of the old Prestolite/Delco starters.

Using the 122-12PM Starter   380 USD

First off, and by a wide margin, most of our customers utilize the 122-12PM starter by modifying the oil cooler diagonal brace.

 

Using the 122-NL Starter    430 USD

Since the advent of the Sky-Tec High-Torque Inline Lycoming starter, many of our customers have chosen to avoid any modification to their oil cooler entirely by simply installing a 122-NL starter.  

 
However, Bill Robek of Stoddard's Aircraft Parts Center in Anchorage, AK suggests you pay special close attention to the clearance between the Sky-Tec NL starter and the vertical oil cooler brackets.  

On some PA-12, PA-18, PA-20, PA-22 or even old PA-28 has an oil cooler in the front/center of the cowl (the "Cheesegrater up Front"), you may have to trim the "ears" (noted as accessory mounting tabs "C" and "D" on the NL Installation Sheet) on the NL starter to clear the oil cooler bracket.  Those ears are sacrificial.  So why are they there?  Well, they were put there to emulate the location of the mid-body bolts on the most popular Prestolite starters that are required by many airframe manufacturers to hang various brackets, accessories, and baffling.  On some of the small Pipers, however, those ears may simply just be in the way.