This has been on my mind for a while as I am a landscaper and regularly tow 8-10K lbs. A 3.4 pullied + supporting mods L67 has around the same power and torque as this 6.0L in the work truck. Do you think that if attached to a good frame, RWD, and a good trans a L67 could easily tow 10,000lbs?

um thats a DEF no

I would say No.
The L67 is a very efficient engine but it'* weak link is heat disapation and towing that much weight would cook the trani IMO.

Doh, I forgot to add the heavy duty cooling system to my list. This is hypathetical as I am not going to buy a full size pickup and drop an L67 in it to find out. Just an interesting thought considering the torque similarities between the L67 and V8 truck motors

I don't see why not, you wouldn't want to lug it down, cause of KR, but if you kept it above like 4500 RPM, good cooling, good tranny, I think it'd pull just fine.

I'm the only person here that tows with an L67 on a somewhat regular basis. I'll say NO.

Never tow more than 3-5k with one. These are FWD, and the drivetrains weren't designed to handle that load.

Don't do it.

Umm, he did say the rhetorical platform would be RWD, so I'm assuming either 4L60 or 700R4. Either of those transmissions should do just fine with the proper cooling.