I just bought a 1977 Ford f-150 custom and on the valve cover it has a sticker that says 351m 400ci . So this motor is a 400 cubic inch correct? Also is it a big block? So is there a 351m that is a 351 cubic inch? Thanks for the info.

 

Hey Haydendh

From what I have researched and gathered, the 351M is a motor in the same class as the Cleveland. I have a 77 F100 with a 351M. Here is a link with some good info, hope it helps.

Ford 400 and 351M Performance Upgrades and Parts - FordMuscle

 

The 351M displaces 351 cubic inches, just like a 351C. It has a block with a much taller deck however. A 400 actually displaces 402 cubic inches in the exact same block as the 351M. Crank and pistons are the only differences between the 351M and 400. 351M has a 3 1/2" stroke, the 400 has a 4" stroke. The early 400 had better, non-smog heads like a 2V Cleveland, all 351M engines and the later 400 had smog heads.

Ignore the sticker on the valve cover, the ALL say that. The engine is a Ford 335 series, and would best be described as a "tall deck" small block.

 

So how do I tell if I have a 351m or a 400?

 

Hey that's a nice article

You can't trust the valve cover because it is to easy to be moved from one engine to another.

A little FYI though, the valve cover will say "family: 351/400" but it will also say "displacement 400" or "displacement 351"

Crankshaft identification is the only %100 way of knowing.

Here's our link to help identify the crankshaft.

Visually identify Ford parts on Pinterest

 

So there is a 351m that's a 351 and a 351m that's a 400 but they are both called 351m?

 

no 2 different motors there is the 400, and thats just 400 no M. then you have a 351M. the M is for modified the 351M is a modified 400. as was said before same block and rods different pistons and crank. you should search and read and 99% of your questions will be answered. not trying to be a jerk but i have searched tons and only asked a few questions.takes just as long to search as ask questions and wait for replies

 

I did search and was still confused if you don't want to answer then move on and be rude on someone else's post.

 

Deleted. See below.

 

no wasnt being rude at all.just stating facts is all. as you can see i too am new to this board. just saying search function is sweet here. im sorry if i hurt your feelings by not sugar coating my reply. alll i did was give you a straight direct answer,folowed by some good advice. you were also given links to the same information that i researched when i first joined this site. once again, im sorry if my direct form of speaking is abrasive to you. just trying to not leave any grey areas. but its almost obvious that you dont understand the answers of the questions you have asked. wish you the best here. but if you think being rude is giving you proper information and sound advice you should join sally's sewing club forum you might get better responses there.
the second thread in this forum is titled 335 TECH TIPS AND TRICKS. one trip through that thread would have answered ALL of your questions and wouldnt have even had to SEARCH lol sir this is being rude

 

Look it's simple if you are tired of answering the same questions then either A. Get off the board. Or B. Just don't answer them lol wow bet you never thought of that one. I didn't call anyone out by name asking for your specific answer , so yes you were rude. And no it didn't bother me I just wanted you to know you were sounding like a ***. I thought maybe I could get some input from grown ups here but just another internet board with some kids on it.

 

This appears addressed to me, so I will respond - the last time I will respond to you as you are now on my ignore list and I will no longer be notified of any of your posts.

You are new to FTE, but I'm not. And I'm not a kid - probably older than you at 67. But I'm known as being very helpful and willing to share what I know or can determine. However, after having helped or tried to help people with the same question several times lately it has gotten old. So, we are asking people to do some of the work to answer their own questions. I gave you a link to a thread about exactly the same thing, and it was less than two weeks ago so was still showing on the first page of threads. So, you didn't do much searching or you would have easily found it.

However, with your attitude I'm sorry I tried to help you and have deleted that information. Good luck to you, but I doubt you will have any such luck on FTE. You've burned your bridge with me and probably with the other regulars.