Well the 351W was derived from the 221-302s It shares a lot of parts with that line of engines.
The 351M was derived from the 400. Only difference is the stroke and piston compression height.
The clevland is well....kind on its own. While it does share some parts and diamentions with the 351M/400 the parts that are different are the block, crank, connecting rods, pushrods, pistons, main bearings and intakes. while the heads are different a lot of them interchange.

 

351W- is from the small block family and shares a few of the same parts as the 302. It is part of the 90 degree V-8 series and was introduced in 1969. It is a member only in design really.

351C - intoduced in 1971 is the newest of the push rod designed motors. It was built for high-performance from the begining. Ford small blocks had heads that did not breath well and Ford made sure the the Cleveland series of motors did not have this problem. With some modification the heads from a 351C will work on a 351W (call a Clevelor), but other than that there is not much that will interchange.

The FE 390 was Fords truck block and it was discontinued in 1971 leaving a hole in the line up, the design of the 351C was changed by adding 1" to the deck height to allow the block to handle 400ci and replace the 390FE. The mains bearing are bigger on the 400 and it uses different rod. 351C pistons will work in a 400 with modification.

351C - went out of production in 1973 when Ford pulled out of racing. There were not enough 351Ws being produced to meet demand so Ford got the bright idea of destroking the 400 to 351 and produced the 351M. There must have been a lot of heavy drug use among the decision makers during this time period, because most of the descisions they made were pretty bad. There was never any real reason to have the 351M. It would have been cheaper to stick a 400 in everything. The only difference between the 351M & 400 is the crank and the pistons.

351C was cast at the cleveland foundry.
351W was cast at the windsor foundry.
400 was cast at the Michigan foundry..... Technically there was not a 351M block as it is the same block as the 400. Some people say the "M" stands for Modified because it was a modified 400. Some claim it stands for Midland. Ford has never stated what the "M" stands for, but given the history for naming blocks for the foundry they were cast in.

 

simple, really....the 351M has the big bell bolt pattern, like that of the 460. The 351W/C has the small bell bolt pattern, like that of the 302. Might want to make sure you have the right tranny first.

 

ok thanks alot guys, especially for the general history of those motors, a great help, so next and should be last question, will the c6 tranny bolt up to the 351m thanks again for your help

 

only if you have the big bell bolt pattern C6

 

If you have a stock 351M then the c-6 will bolt up to it. Any 400 built after 1973 (1974 and up) were all big block bell housings (C-6). The rare small block castings were only made 1971-1973. Look for blocks cast after 1977.

 

390 went out of production in 1976, hence the 400 was put in trucks starting in 1977.

351C went out of production in 1974 in the US and in 1982/3 in Australia.

400 was cast at not only the MCC but also the Cleveland Foundry (CF marking) and Detroit Iron Foundry (DIF marking).

 

I pulled the dates from "A Chronology of Ford Engines"

The 390 was still in production up into the 80's, but not full production. If you ordered a replacement block from Ford in 1980 they would send you a 390 truck block that could be made into 427/428. They are easy to spot because of the ribs that are cast into the side of the block.

The 400 was cast in the Cleveland foundry after the 351C was discontiuned, but they would have created a lot of confusion if they started calling the new 351M a 351C. The Michigan plant was the first plant to cast the 400 wihich would be turned into a 351M.

The dates I listed were for full production castings. Casting will still continue for any motor after this date as an inventory of warranty blocks and replacement sales. Ford still had to support the blocks for several years after they were discontinued.

I do not claim the dates are exact, just from the book. I know that 390s were used in trucks until 1977.

 

"The rare small block castings were only made 1971-1973"

One minor correction. The small bellhousing 400 was '73 only.

 

351??? - FSB Forums

If you look at this link and scroll down you will see a 400 with the small bellhousing. D1AE casting. Which makes it a 1971 block.

 

Be careful quoting any Ford book. You'll find them claiming that the 400FMX blocks had a casting code of D3xx instead of D1AE. This has been discussed to death for a good 5-6 years now on several of these boards. I know of 10 blocks and none have the D3xx code. I won't get into make and model and which years these were sold because Ford left no absolute proof....not to mention that hundreds of posts have hashed it out on this board, FSB, and the 335 Series board by both owners and "experts".

As for the 390 service blocks, those were 391FT blocks and were only sold to replace the 428 (not the 427) as there was just enough meat in the bores to take a 4.13" bore but not nearly enough for the 427s 4.23 bore. Ask how I know. I've had some of these in the past and some would not take a .080" over bore while others would, that's just typical thin-wall casting issues.

I can't claim how long Ford continues to produce anything. Ford built 390 Industrial engines for awhile until 370/460 production took over completely....they recently did the same a few years ago when they finally phased out the 460 industrial engine for the 6.8L V-10. But on the whole, Ford usually kills off anytype of back stock and/or warrenty parts production within 10 years or so (that does vary widely). At least that has been my experience when it comes to picking up parts from a Ford counter. Some things they have after 10 years and many they don't.

I've had many early MCC cast 400s plus CF and DIF blocks. The D1AE-A2C (400FMX) was a MCC casting. BTW, here are 2 pics of my D1AE-A2C block, one with an Aussie 351C hydro clutch bellhousing bolted.

 

I agree, given Ford's history for naming their blocks from the foundry they were cast in, seems reasonable to assume the 351M would stand for 351 Michigan.

 

Youre very right falcon, My 73 400 has the exact casting code that the small bellhousing patterns said would have, but mine doesnt...

 

Thanks for the pictures. I do not claim any of the Ford books are right. It is just all I have to go by. I am still looking for the 400 4V that they claim was made in 1971 with 4-barrel carb and intake (260hp & 400 ftlbs). There was a "stock" 4 barrel cast iron intake for a 400 that showed up on e-bay a while back, but no one proved that was what it really was and it sold for a good bit of money.

You are right about the D1AE and the D3AE. All of the ones I have seen (all 4 of them... so not many) were D1AE castings. The D3AE are reported by Tom Monroe in his "Ford V8 Engines" where he claims he tried to swap in a 400 (D3AE) from a car and found it had the small bellhousing. He claims however that 1973 was the only year for the small bellhousing.