This is all I have on the 241 (part of a MSWord file), and I don't remember exactly where I got this:
NP241
Type: Part-time, aluminum, chain-driven case
Low range: 2.72:1
Applications: ’88-2000 GM pickups, ’89-’91 Blazers, Suburbans, and Jimmys, ’88-’93 Ramchargers and pickups, and ’94-present Dodge ¾- and 1-ton trucks.
In 1988 New Process proved that you could build a chain-driven case to handle serious torque. The NP241 is strong enough for your big-block–powered rig, and with a 2.72 low range (Mepco has a 4:1 kit) you can crawl all over your NP205 buddies. A heavy-duty version of this transfer case is used in the Ram 2500 with the snowplow preparation package, all Cummins diesel-powered Rams, and Ram 3500 dualies. This NP241 HD has provisions for a PTO. Be careful when shopping for this case as GM has an IFS version with the front output on the driver side and a solid axle version with the front output on the passenger side. Dodge also played this game when it switched to the new body style in 1994 and moved the differential to the wrong side. One final word of caution, the NP241 could use either a mechanical or electronic drive for the speedometer, so make sure you get one that will work with your speedometer or vehicle speed sensor (VSS).