199x to end of manufacture Mazda B-series and Ford Ranger with M5OD manual transmission. Most will be either 4-cylinder or 3.0 V-6, and standard cab, although the transmission was offered in larger trucks with the 4.0. Earlier Rangers and B-series might have had a T-K five-speed manual that was not as well lubricated when towed. I'm not sure of the cutoff year, sometime 1993 or later.
Nissan Frontier with 5-speed OD manual transmission. Most will be 4-cyl standard cab, I had a real hard time finding anything with a V-6, which is why I ended up with the 2001 Ranger instead of a Frontier.
Mitsubishi, Toyota, GM with the S-10 Chevy and S-15 GMC did not recommend towing with the manual transmission in neutral. GM got to flat towing, manual or automatic in 4x4, by changing the transfer case they used.
The transfer case for earlier 4x4 GM compact automatics was not towable, even in in neutral. The transfer case used by Mitsubishi and Toyota in compact trucks was not towable. Generalizations about transfer cases in neutral are no better than the generalization that manual transmissions are all towable. If anything, a TC of the wrong type will grenade during towing a lot sooner than the output shaft bearing of a manual transmission will seize.
Tom Test
Itasca Spirit 29B