help please 351m 400

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Jul 21, 2020 | 06:59 AM

#16

Red Mercury

Tuned

Joined: Mar 2010

Posts: 387

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Quote:

Originally Posted by bluovl

"50-60K" really? I ran my 400 for 19 yrs before replacing it. I don't remember how many miles it had on it. It was a daily driver, and towed our trailer. Even then it good oil pressure and no knocks, but I changed oil every 4k miles without fail.

Likewise. I have a stock 400 with 275,000 original miles. I finally pulled it as the oil consumption was getting excessive--still ran fine. I "temporarily" swapped it for a 351M that now has approximately 150,000 miles. I liked the 400 better than the 351M--the 351M is in a 1979 F150 4WD with 3.50 gears and doesn't have much power for towing a trailer. I change oil as soon as it's getting dark brown/black in colour, never paid attention to the odometer since the oil seems to get dirty much sooner when these engines have higher mileage.

Jul 21, 2020 | 09:42 AM

#17

79dump

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Joined: Jul 2020

Posts: 18

Likes: 2

From: Pa. USA

I only have the heads off my old engine, im pretty sure the bottom end is good but i want to get it out of the truck and apart before i make any final decisions on what to put back together. Unfortunately i am recouping from some minor medical stuff and the wife wont let me play with my truck..