One example of the strong verb would be OE
scrinc(an), scranc, scrunc(on), the MnE
shrink, shrank, shrunk, with pretty much the same pronunciation in OE as in MnE, slight differences in the vowel sounds that aren't important to this topic. The
sc in OE was almost always pronounced as MnE
sh.
While
shrink has stayed as it was in OE there are some that have changed considerably.. One good example is
sneak. Most (if not all) grammarians today would call it a regular (weak) verb, but in OE it was strong. The forms were
snīc(an), snāc, snic(on), which, as near as I can guess, would be
sneak, snoke, snick(en) in MnE.
Note: I am using the ^ over a vowel to indicate a macron, not available in any font I know of.
My main sources here are
A Guide to Old English by Bruce Mitchell and Fred C. Robinson and
A Concise Anglo-Saxon Dictionary by J.R. Clark Hall. The latter is also available in scanned form on line at
http://www.ling.upenn.edu/~kurisuto/germanic/oe_clarkhall_about.html