351 ???

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Mar 12, 2007 | 10:50 PM

mid tenn

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351 ???

Got this 59 F-100 with a early 70's 351 in it, with auto trans. Was told it might be a 351 M (modified) ? How do I determine what I have here ? Thanks.

Mar 12, 2007 | 10:56 PM

51dueller

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From: Saskatoon SK Canada

6 valve cover bolts = 289/302/351W
7 valve cover bolts = 429/460
8 valve cover bolts = 351C/351M/400

Mar 13, 2007 | 08:07 PM

mid tenn

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I have 8 cover bolts, how do I tell the difference in a 351C and M ?? I was told it was a "M" because of the heads.

Mar 13, 2007 | 08:44 PM

53fatfndr

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From: Earth

Quote:

Originally Posted by mid tenn

I have 8 cover bolts, how do I tell the difference in a 351C and M ?? I was told it was a "M" because of the heads.

Pull the number off the back of the block, near the oil pressure sender, and then post it up in the 335 series engine forum.

Mar 13, 2007 | 10:11 PM

havi

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From: Northshore, MN

or measure the width of the intake and post in the 335 series forum.

Mar 13, 2007 | 10:26 PM

airharley

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From: Escondido, CA

M-block engines have the taller intake manifold front mating surface (almost an inch above the distributor mounting hole and front cover housing). There is about a 1" rib cast onto the block on the taller 351M/400 which runs along side the distributor going from the front of the block extension back to the intake manifold.

Last edited by airharley; Mar 13, 2007 at 10:47 PM. Reason: bad link

Mar 14, 2007 | 09:25 AM

irondragon79

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You won't be able to tell the differance between a 351C and a 351M by the heads since they are identical, however the block (intake width) will be differant.. 351M is wider.

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Mar 16, 2007 | 08:53 PM

F-1CLEVELAND

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stock ford intake? 351 m two barrel only 351 c head casting valve cover area 2 or 4 incorners to denote 2bbl or 4bbl and 351c typical smallblock bellhousing bolt pattern and 351m 400m bigblock bell (c6 trans by any chance?) Yes rib near distibuter is correct and easiest! 351m has it.