I dont know of a GM 3800 engine (Supercharged or NA) that hasn't needed a head gasket around 100k miles. Same with a 3100.

My 4.5 engine had 145k miles before I did the chain. It did have 12° of stretch - but it also had aluminum-backed rails so could have probably gone longer, I figured I'd do it to do it and that it would allow me to write a nice DIY article. Still dont know why MB switched to plastic rails!

My 4.5 was rated for 230 HP and 280 ft/lbs of torque. That's 51.11 HP / liter and 62.22 torques / liter. Compare that to my pushrod V8 5.7 hemi that's rated for 340 HP and 390 ft/lbs of torque: 59.65 HP / liter and 68.42 torques / liter. My cast iron 4.5 was designed and first mass produced in 1970. My 5.7 was designed and first mass produced around 2004. You would think 34 years would net a larger percentage gain!

Now, look at modern MB engines - 5.5L n/a V8 produces a fair amount more than my 5.7 n/a V8...

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k