You most likely need a starter with 3/8" offset. Most 3-4 speeds use those. The autos and 5 speeds use a 3/4" offset.
Offset is the distance from the mounting surface of the starter to the engine side of the ring gear. Lay a straight edge across the hole in the bellhousing for the starter and measure from it to the engine sid eof the ring gear.
I have been very happy with my Powermaster starter. 3 yrs old and it will spin my 13:1 383W easily, even with the timing locked at 38° initial. They have 3 levels, the lowest one is just a late model Ford mini-starter. They rate it at 160 ft/lbs of torque. $169 new from Summit. You can also get a rebuilt one from Auto Zone, etc for $89 + $40 core charge.
If you want to step up to a stronger starter Powermaster has two stronger versions. One at 180 ft lbs, another at 200 ft lbs. I have the 200. Costs $199 from Summit, has a clockable nose piece so you an move it to clear headers, etc.
Take a look:
The Powermaster site:
http://www.powermastermotorsports.com/Racing/racing.html
Later,
David Cole