it would be fun to see a previous model and a 2027 bone stock on the dyno next to each other.
I hate to agree with my fellow Coloradan but I do have some questions since it doesn’t appear to be just additional drag (the old net versus gross) and the PSD is unaffected.
Does it make it or break it? No. I would buy the 7.3 for a DD or to be modded for desert with Carli toys. 6.7 would be my preference for towing heavy/regular. For work it just means we are getting 7.3s instead of 6.8s so just annoyed with the cost. We still get 6.7s for heavy applications.
But to go from something that was claimed to be “under rated” to lower ratings doesn’t feel great especially when no manufacturer ever wants to lower power ratings, especially below a direct competitor. Remember we talk about gross/net from the muscle car era but emissions, compression and breathing played a big part in going from 375 hp small blocks to 150 hp, far more than the alternator and water pump.
On my GMT-800 with the 8.1/496 it was derated from 345hp/455 to 330/440 primarily due to the 4L85E supposedly not standing up compared to the Allison 1000 in theory. That being said, a simple catback could get over 17 rwhp so sound was actually likely the main driver. The engine was bullet proof and I beat on the transmission for 200k miles with no issues. In heavy applications it had dual 2.5” tailpipes and dual mufflers. The light application had two cats choked into one muffler with a single 2.5” tailpipe (after a Y). The stock Mercury Magnum boat engine was 425 hp and there was plenty of room above that.
