If you have an early engine - not a 272/292 or 312 - this is an "A" casting pump.......(smaller size than the "B" on our later model engines).http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=370332702571&viewitem=&sspagename=STRK%3AMEWAX%3AIT