Diesel engine swap

[TwoFiftyShifter]

I think a 6.0 vs 454 is a good matchup. The 454 needs to to be bigger since the 6.0 is a newer and more efficient powerplant. Sure, the wildest drag setups are usually 572s, but give that another 15 years. Or maybe not. BBC is awesome so long as you don't fret your fuel mileage.

[Bigdually]

Since we're on the topic, I'll chime in with real world experience here. Had an 09 3500 GMC with 6.0 automatic and 4.10s. Biggest disappointment I've ever had, towed crappy, wouldn't make any hill without SCREAMING high RPMs, and I NEVER saw anything over 11 MPG.

Best buddy has a crew cab square dually. Newer GM crate 454, TH400, 4.10s or 4.11s. Will tow circles around the LS truck I had, rarely downshifts, and averages.... Yep! About 11 MPG. I'll take the BB any given day. The 6.0 is IMO the most disappointing engine for a tow rig that ever there was. The low end torque just isn't there.

There is still NO replacement for displacement. Big HP numbers are impressive, but are derived from torque and RPM. Torque is the variable that gets things moving

[LT7A]

Very interesting thread. Thanks to the participants. The answers show some biases, but we're all humans. DD being an LS and my projects trucks having 454s, I read through the biases to the facts with unabashed interest. I'm an off-the-line torque guy, so pre-LS is my hobby bias. But my DD gets going nicely once the LS spins up. The pre-LS preference for towing makes sense to me.