Cast Iron Parts


M-Block 351M/400 Parts ReferenceCast Iron Parts Copyright © 2002-2003 Dave Resch
All rights reserved.Letter of permission on hand, thank you Dave Resch  ~BlizzND


This section lists Ford part numbers and casting ID codes for the following major cast iron parts of M-block (351M/400) engines:

  • Engine blocks
  • Cylinder heads
  • Crankshafts
  • Intake and exhaust manifolds

 

Check out this section if you are not familiar with Ford part numbers and ID codes.

Engine blocks

All 351M/400 engine blocks were cast at one of the following foundries:

Top: Four variants of the Cleveland Foundry code. Bottom: Dearborn Iron Foundry code (left) and Michigan Casting Center code (right).

 

  • Cleveland Foundry
    (casting code CF)
  • Dearborn Iron Foundry
    (casting code DIF)
  • Michigan Casting Center
    (casting code MCC)

 

In MY1971 through MY1972, engine blocks for 400s were cast mostly at the Dearborn Iron Foundry, with some cast at the Cleveland Foundry.

After MY1972, all 351M/400 engine blocks were cast at either the Cleveland Foundry or the Michigan Casting Center.

The foundry casting code on all M-block engine blocks appears at the top rear of the block, behind the intake manifold, near the oil pressure sending unit hole.

Engine blocks from the Dearborn Iron Foundry and Michigan Casting Center have the casting date code next to the foundry code. Engine blocks from the Cleveland Foundry have the casting date code on the right side of the block, near the block casting ID code.

Foundry casting codes and date codes are significant for M-block engine blocks because some blocks that were cast before March 2, 1977 at the Michigan Casting Center are prone to water jacket cracking in the lifter valley area. Blocks cast at the Michigan Casting Center after that date do not have the cracking problem.

To avoid the water jacket cracking problem, watch out for engine blocks with the Michigan Casting Center foundry mark and a date code of 7C02 or earlier.

The following table lists M-block engine block part numbers and casting ID codes.

Model Year Part Number Casting ID Notes
1971-1973 D1AE-6010-A D1AE-A
D1AE-AC
DIF or CF foundry code.
1973 D3AE-6010-B D1AE-A2C
D3AE-B
Rare 400 w/ small-block bell housing. MCC foundry code.
1974 D4AE-6010-B D4AE-B1A
D4AE-B2A
CF or MCC foundry code.
1975-1979 D5AE-6010-A D5AE-A
D5AE-AA
D5AE-A1A
D5AE-A2A
CF or MCC foundry code. 351M/400 car only.
1978-1979 D8AE-6010-A D8AE-A
D8AE-AA
D8AE-A1A
CF or MCC foundry code. Reinforced main webs. 351M/400 car only.
1977-1982 D7TE-6010-A D7TE-A1A
D7TE-A2A
D7TE-A2B
D7TE-A3A
CF or MCC foundry code. Reinforced main webs. 351M/400 truck only.

Cylinder heads

All M-block cylinder heads were cast at one of the following foundries:

  • Cleveland Foundry (casting code CF)
  • Dearborn Iron Foundry (casting code DIF)
  • Michigan Casting Center (casting code MCC)

 

Foundry codes and casting date codes on all M-block cylinder heads are located on the top of the head, usually on the intake runners. You have to remove the valve cover to see those codes.

Cylinder heads from the Dearborn Iron Foundry and Michigan Casting Center have casting ID codes on top of the intake runners. Cylinder heads from the Cleveland Foundry have casting ID codes on the bottom of the intake runners. You have to remove the intake manifold to see the casting ID codes on a CF cylinder head.

All 351C cylinder heads have a number “2” or “4” cast into the upper corners of the head. Those casting marks identify the head as either a 351C 2V or 351C 4V head. Early production (MY1971-MY1974) M-block cylinder heads have either no mark in that spot, or a “2” like the 351C 2V heads.

After the 1974 model year, all M-block cylinder heads cast at the Cleveland Foundry have an “M” cast into the top corners of the head. Some M-block cylinder heads cast at the Michigan Casting Center have unmarked corners, like early-production heads, and others have the “M” mark.

In later production (’75-up) M-block cylinder heads, there were subtle design differences (e.g., combustion chamber sizes) in cylinder heads with the same casting ID code. In some cases, the differences seem to be related to the foundry code, while others seem to be related to the casting date. M-block cylinder head combustion chamber sizes are listed in the second table below.

The following table lists M-block cylinder head part numbers and casting ID codes.

Model Year Part Number Casting ID Notes
1971 D1AE-6049-A D1AE-A1A
D1AE-A1B
Original 400 design.
No AIR passages.
1971-1973 D1AE-6049-A D1AE-A1C
D1AE-A2C
Revised design w/ smaller chambers.
Used until mid-year ’73.
1973-1974 D3AE-6049-G D3AE-G2B ’73 mid-year change.
AIR passages drilled.
1975-1979 D5AE-6049-A D5AE-AA
D5AE-A1A
D5AE-A2A
D5AE-A3A
All 351M/400 cars.
Chamber sizes vary from 74.5cc to 78.4cc.
More restrictive exhaust ports with “pot belly” valve boss.
1977-1982 D5AE-6049-A D5AE-AA
D5AE-A1A
D5AE-A2A
D5AE-A3A
All 351M/400 trucks.
The following table lists casting ID codes, production dates, and combustion chamber sizes of M-block cylinder heads.
Cylinder Head Casting ID Chamber Volume
D1AE-A1A,A1B (1971 400) 77.8cc
D1AE-A1C,A2C (’71-’73 400) 75.6cc
D3AE-G2B (mid-year ’73-’74 400) 75.6cc
D5AE-AA,A1A (’75-’76 351M/400) 74.5cc
D5AE-AA (’77-later 351M/400, CF) 76.9cc
D5AE-AA (’77-later 351M/400, MCC) 78.4cc
D5AE-A2A (’77-later 351M/400) 74.5cc
D5AE-A3A (’77-later 351M/400) 74.5cc

Crankshafts

Many people would like to know of an easy way to tell the difference between a 351M and a 400. Since the crankshaft is the main component that determines whether the engine is a 351M or a 400, the only reliable way to identify an M-block engine as either a 351M or a 400 is to verify the crankshaft casting ID code. This requires, at a minimum, removing the oil pan to view the crankshaft where the casting ID code appears.

Here’s why you can’t distinguish a 351M from a 400 by inserting a rod through a spark plug hole to measure the stroke.
Ford used the same components (engine blocks, cylinder heads, manifolds, etc.) to make both 351M and 400 engines. Therefore, you cannot rely on the casting ID codes or part numbers of any external component to distinguish a 351M from a 400.Any 400 manufactured in any year can be rebuilt as a 351M by simply substituting the 351M crankshaft and pistons for the 400 parts.Engine ID tags and calibration stickers are easily swapped from one engine to another, and even if they are not swapped, there is no way to tell whether an engine was rebuilt with 351M components without looking at the crankshaft.The following table lists M-block crankshaft part numbers and casting ID codes.
Model Year Part Number Casting ID Notes
1971 D1AE-6303-A 5M Original 400 crankshaft.
1972-1973 D2AE-6303-A 5MA
5MAB
400 crankshaft, car only.
1974-1977 D4AE-6303-B 5MA
5MAB
400 crankshaft, car only.
1975-1976 D5AE-6303-A 1K Original 351M crankshaft.
1977-1982 D7AE-6303-A 1KA All ’77-up 351M car and truck.
1977-1982 D7TE-6303-A 5MA
5MAB
All ’78-up 400 car and ’77-up 400 truck.
M-block crankshaft casting ID codes are located on either the first counterweight (opposite the first throw at the front of the engine), or on the side of the first throw. Casting ID codes are recessed into the unfinished (raw cast) surface. Sometimes the characters are faint, so you may have to thoroughly clean the area with a solvent to find the ID code.All 351M and 400 crankshafts are interchangeable, as long as you use the corresponding pistons. You can use any 351M or 400 crankshaft in any M-block engine block. Main bearings are different for ’77-up truck blocks (D7TE) and ’78-up car blocks (D8AE).

Intake and exhaust manifolds                                                                                             All M-block intake and exhaust manifolds were cast at one of the following foundries:

  • Cleveland Foundry (casting code CF)
  • Dearborn Iron Foundry (casting code DIF)
  • Michigan Casting Center (casting code MCC)

 

Intake manifolds for early 400s (MY1971-MY1972) were cast mostly at the Dearborn Iron Foundry, with some cast at the Cleveland Foundry. After MY1972, all M-block intake manifolds were cast at either the Cleveland Foundry or the Michigan Casting Center.

Exhaust manifolds were cast at the Cleveland Foundry until the end of MY1974. After MY1974, M-block exhaust manifolds were cast at either the Cleveland Foundry or the Michigan Casting Center.

The following table lists M-block intake manifold part numbers and casting ID codes.

Model Year Part Number Casting ID Notes
1971 D1AE-9424-A D1AE-9425-AC All 400.
1972 D2SE-9424-A D2SE-9425-AA All 400.
1973-1974 D3AE-9424-B D3AE-9425-BA All 400.
1975 D5AE-9424-C D5AE-9425-CC All 351M/400.
1976 D5AE-9424-C D5AE-9425-CD All 351M/400.
1977-1979 D7TE-9424-A D7TE-9425-JA All 351M/400, car and truck.
1980-1982 E0TE-9424-B D7TE-9425-SA D7TE-9425-SB All 351M/400, truck only.
The following table lists M-block exhaust manifold part numbers and casting ID codes.
Model Year Part Number Casting ID Notes
1971-1974 D1AE-9431-A (left)
D1AE-9430-A (right)
D1AE-A
D1AE-AA
All 400.
1975-1979 D5AE-9431-A (left)
D5AE-9430-A (right)
D5AE-A
D5AE-AB
All 351M/400 cars.
1977-1982 D5AE-9431-A (left)
D7TE-9430-A (right)
D5AE-A
D5AE-AB
D7TE-A
D7TE-AB
All 351M/400 truck.
Although 351C 2V exhaust manifolds are interchangeable with M-block exhaust manifolds, Ford designed separate manifolds for the 400. This was probably because the 400’s taller deck height made it larger and wider than the 351C.All M-blocks from ’71 to ’82, both car and truck engines, use the same type of exhaust manifold on the driver’s side (left). All M-block car engines from ’71 to ’79 use a car-only exhaust manifold on the passenger side (right).When the M-block was introduced in trucks in MY1977, the narrower truck chassis required the passenger side (right) exhaust manifold to be redesigned so that the manifold’s lower flange would clear the frame rail. All 351M and 400 truck and van engines from ’77 to ’82 use a truck-only exhaust manifold on the passenger side (right).

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