Baseball from 1900-1920 set pathetic home run totals, but the pitching won't be touched, ever.
Ed Walsh '08 464 IP
http://www.baseball-almanac.com/recbooks/rb_ip.shtml
Like Jeremy Schaap said, 1727 innings without being relieved.
Irv Young, 378 IP could never be broken, especially by a rookie!
Even Mike Marshall ('74) if these are too old for you, 208 IP by a reliever!