DRASTIC overheating on your m117 is the result of 3 possible things:

1) Not enough coolant
2) Blocked passageway to the rad (collapsed/kinked hose, bad t-stat)
3) Bad water pump

If your system is circulating an ample amount of coolant, no matter how hard your M117 is working or revving (within reason), it won't overheat if it's moving. If you overheat rapidly even going downhill with your foot off the gas, you need to check these 3. From the sound of it, #3 is most likely, especially if a low-quality pump was used.

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2024 CR-V Hybrid

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1972 280SE 4.5
2018 Durango R/T, 2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k