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Jul 13, 2004 | 08:13 PM

jazzy66

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Joined: May 2001

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From: South

400 modified

I was wanting to know if a 400 modified block is the same block as a 390. I was wanting to use my intake and heads from the 390

Thanks

Jul 13, 2004 | 09:14 PM

Putt

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From: Colville, Washington

NO. The FE is completely different from the 351m/400m engines.

Jul 14, 2004 | 08:57 AM

dhermesc

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From: Near Wamego KS

Two completely differant blocks - like trying to bolt your 390 heads onto a Chevy 396.

Jul 14, 2004 | 09:45 AM

banjopicker66

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Joined: Apr 2002

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From: Coal country

STOP WHAT YOU ARE DOING.
PUT YOUR TOOLS DOWN.
STEP AWAY FROM THE 400.
SECURITY PERSONNEL WILL TAKE OVER FROM HERE.

Seriously, unless you have no other options, stay away from the 351M and 400M engines. They were one of Ford's WORST ideas.

The biggest problem is their oiling path, in that the rods and mains get oil pressure last. They just aren't that durable.

Just my thoughts!

Jul 14, 2004 | 10:30 AM

PROSTOCK

Cargo Master

Joined: Feb 2004

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From: Central Texas

Hey hold on Banjo! I've got a 78 Bronco with over 250,000 miles on a 400. They ain't THAT bad!

Jul 14, 2004 | 11:07 AM

dhermesc

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From: Near Wamego KS

We had several 351Ms and 400s in 3/4 ton and one ton pickups - except for the lousy fuel mileage they ran out well. Older one ton had a carbed 351M and it humbled an earlier 90s one ton with a 351W. Worst engine ever put in a Ford was the 360.

Jul 14, 2004 | 11:07 AM

banjopicker66

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Joined: Apr 2002

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From: Coal country

Great! Every 351/400M I have ever worked on has been in sorry shape by the time it got to me. Most mechs I have interacted with also feel the same way - but then, evey one has an opinion, whether it be valid or not.
Do you have any ideas what contributed to that long life? Did you do or not do anything special?

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Jul 14, 2004 | 11:24 AM

PROSTOCK

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From: Central Texas

13 years ago I put a cam, alum 4v intake, and 4v 460 valves in the heads, along with a mild port job. The Bronco has a C6, runs 35" tires w/ 3:50 gears and has towed a boat for many of those miles. It averages 10mpg pulling the boat w/ ac and cruise. I'm not saying they're the best Ford motor, but I can't complain! Routine maintenance since then is all it has had. NOW, all that said, it is a little tired and I have another 400 to plug back in when I have to or get the time. But I'm sure not gonna change to anything else(i.e. 351W, 460, etc). My buddy changed his 400 to a 460 and swore it wasn't worth the time, hassle, and especially $$$$$$$$$!