Ok I'm a first timer so don't laugh at my ignorance.....I recently bought a 78 f150 ranger lariat long bed all original 351m pure stock 2wd 85xxx miles The truck runs but not like it should and not like I want it to. I'm thinking of rebuilding it putting a mild cam,headers,4 barrel,etc but this will be my first attempt at even being inside a motor so any words of advice are greatly appreciated Im trying to do this on the cheap side too.

 

First, welcome to FTE! This is the place to be. There are people with lots of knowledge in each sub-forum, but some of the sub-forums are slower to respond than others - like this one. But eventually the guys drop in and they have a wealth of knowledge.

Second, one thing that tends to put them of is textese and the lack of punctuation. Some of us are OLD, and especially me, and have a hard time wrapping our heads around large blocks of text. So thank you for helping us.

Third, none of us were born with knowledge about engines - although what little I have was acquired loooong ago. So, we don't look down on those that don't yet know, and someone who is willing to say he doesn't know is well on the way to learning.

Next, let's talk about rebuilding an engine. These engines are no different than any other of the era from a rebuilding standpoint. But there are certain things all engines need, like proper torque values and assembly order, so good instructions are necessary. And the absolute best reference is Ford's factory shop manual. You can rely on the values and instructions there, but you never know about others like Chiltons or Clymers. So, I strongly recommend the factory manual.

Then there are tools. Do you have access to torque wrenches? Have you used Plastigage? Do you have a ring expander and compressor? These tools are very nice to have and, like the torque wrenches, are necessary.

Last, what is your plan for the engine? Are you aware of the lack of pistons that provide reasonable compression for the M? You won't be able to raise the compression above 8:1, so won't get dramatic amounts of power with the rebuild. However, an 8:1 351M with a good cam and timing set can do pretty well, as Rusty proves. But, if you were to find a crank from a 400 then you are into a new world. Tim Meyer has the needed pistons and you can have 9.5:1, which will bring the power up nicely. The same heads, cam, headers, intake, exhaust, etc fit the 400 as the M since the only difference is crank and pistons.

Then there's the oiling system. These engines were designed with a system that causes low oil pressure. But Tim has a mod for that which brings the pressure up nicely and costs almost nothing. You can do the mod yourself or your machine shop might do it. But, you could also ship your engine to Tim and have him do all the machine work and build it for you.

 

I have access to a torque wrench but things lik a piston ring compressor and stretcher are tools I will have to buy along the way I would like to build it myself just cause i want to learn and where could a find a factory manual at? I've read almost everything I can find online about the engine....what parts are interchangeable,what aint but I don't want to believe the rong specs or anything like that and I apologize for the big block haha I'm not the best at punctuations.

 

I googled "1978 Ford light trucks manual" and got lots of hits. Here's one on CD: . But, there are advantages and disadvantages to electronic versions. An advantage for some versions, including this one, is that you can search for terms. However, my experience with that vendor is that his OCR step is not thorough and only about 10% of the terms are found in the search. A disadvantage is that you have to have it on a tablet or print it to have it "ready to hand" while working on something.

 

I will order it and can I find a crank out of any 400? Could I just buy one?

 

As Gary said, we all had to learn so go for it. All of us will be glad to help you along the way, DONT BE AFRAID to ask about what you dont know. Tim Meyer is your best source for these engines, CALL HIM. Heres the cheapest ive found cranks other than looking for an old engine for sale. GOOD LUCK with your build.

Crankshaft Kit 71-82 FORD 400/6.6L V8 5MA, 5MAB, MAIN JOURNAL SIZE 3.000

 

A crank out of any 400 may work. The "may" depends on the quality of the main journals. If they can be turned down .010" and be round and smooth it'll be fine. So you don't want one with big nicks on it.