Looking at the 1101, 1102, and 1103 I see some strange claims.
1101 has the least lift (398/421) and duration (194/204)
1102 has a little more (421/444 lift, 204/214 duration)
1103 has even more (444/466 lift, 214/224 duration)
However, the 1101 claims to rev to higher rpm (4500) than the 1102 (4000).
As they get bigger, the rpm they come on at increases (idle, 1500, 1600) which makes sense.
All 3 have 112 LSA.
I have a Comp Cams 252H (CL12-205-2), 425 lift, 206 duration. It's a good cam for a work truck. The 1102 looks to have similar characteristics to what I have, but with more lift/duration on exhaust. It should work pretty well for a tow rig, and I'd expect it to work well off idle even though they say 1500 and up.
While you have it apart, I'd suggest putting in some basic roller rockers.
http://www.summitracing.com/parts/sum-141506 work well for a truck motor, and are cheap.