7.4L 1990s era Chevy/GMC V8 Suburbans opinions??

Joined
Dec 31, 2017
Messages
12,553
Location
SE British Columbia, Canada
The 454 has tons of torque, but is short on the HP curve because the torque drops off quickly. I had a 93 4x4 with a 5.7. Had to eventually put in a new fuel pump and ignition module, otherwise it was fine until it lost reverse gear and I sold it to a mechanic. Keep in mind it has two air conditioners front and back. The ac lines run under the passenger side and are prone to rust. You can easily get front fenders if they rust. You can also get a rear fender patch where condensation from the tailpipe causes rust. Mine is probably out there someplace.

8661B2A6-414A-404B-AE04-DEB1395AAEA0.png
 
Last edited:
Joined
Dec 31, 2017
Messages
12,553
Location
SE British Columbia, Canada
I have a 98 K3500 with the 7.4L/4L80E and its been pretty reliable. I bought it in 2007 with 94,000 miles on it and it now has 122,000. Some of the gauges in the instrument cluster are kind of wonky and it's not the quietest engine but it pulls anything I need it to pull.

It did break down on me recently and it was the coolant temp sensor, the one for the engine management and not the one for the gauge.

I get around 12-13 mpg empty and 8-9 towing. I'm sure a suburban would get a little worse since it's a heavier vehicle.
You know, that’s not all that bad. My 2008 3/4 ton 4x4 Burb gets 15 mpg on the highway at 65 mph and 9.5 mpg towing a 7000 lb 26 ft travel trailer. It’s hardly 15% better.
 
Last edited:
  • Like
Reactions: wtd
Top