Compare the ones here http://www.skidim.com/products.asp?dept=1174
and match with your application.
Delco is GM's "house" brand; Prestolite is typically Ford -- that narrows things down a bit.
2005 X2, Viper Red, MCX, OJ TZ-X5 prop, PPass, rear 750 sacs, KGB, IBS, Bennett Wake Plate, custom wake shaper
(previous) 2001 X5, 1991 TriStar 190