so if I put the crank shaft from the 400 and the pistons would I have to bore out my 351 to make those parts fit?

 

No, the bore size between a 400 and the 351m are the same.

 

yeah, good thing is heads, intake, motor mounts, all peripherals interchange. If you have to bore to even up cylinder, you may have needed new pistons anyway, so if you get your hands on a new or used 4 inch crank buy the 400 pistons too. Almost everyone here recommends the flat tops (but they are very hard to find). Sometimes one of the rebuilders gets extra sets and may sell them or ebay. make sure 400 FORD .

 

ok thanks for the help guy I'm going to look at the 400 that my boss said I could have and make sure that it's no cracked or anything like that.

 

Hey, that's a great start having a donor engine. Check the crank casting no. first off.

Some say don't rebuild certain blocks. In back of engine behind the oil sending unit on top of block are cast codes. look for the MCC or CF. If its MCC check the numbers on the block against bubbuf250s reference to make sure it is not from the period where they were having casting problems leading to cracking in lifter valley. They say if it is, then use a block from a different period/casting center for rebuild, while others state that is not true if the motor has been used and not showing cracking signs.

 

I used to be in the "well if it's lasted this long without cracking then it's probably good" camp but after talking with 2 guys who spent some decent coin to rebuild engines with bad date codes and then having the blocks crack after the rebuild I've switched over to the "if it's got a bad code then toss it" camp.

 

If Bill says it I'd listen to him Iceman.

 

how do i find the codes of the bad blocks thanks.

 

My "reference book" built from articles and answers to questions I posted on this forum is in the car. I did a search of this forum (top right of screen) using key words "casting dates". Here's what came up:

https://www.ford-trucks.com/forums/s...=casting+dates

 

ok guys I went and looked at the engine that my boss said that I could have and it's not a 428 it's a 460. my question is how much more gas would the 460 burn over my 351m that's in my truck now? and how much more power would the 460 have? thanks

 

The question you asked about how much power could the C6 handle, I'd say right around 700 HP. A well tuned 460 will get you more power, and wouldn't use a hole lot more gas, maybe 2 mpg at the most.
You might want to bore out the block to even up cylinders and put some new poistions to bump up the compression ratio, good carb(600Cfm+) and intake, headers and exhaust, timing, cam and lifters, and a few other little things would be good for the 351M400, but depending on when the 460 was made you might not need to do some of that.
Because like said above if it was before that emmissions crap then it should have a good CR as is.

 

I must say that you guys have helped out alot. I just bought a 77 f150 custom that was born with a 302 but now has from what I have been told is eithes a 351m or 400 it is good to know that they are so easily interchanged because I am not certain which engine it is for sure and there is no sticker on the valve cover. this is going to be my first attempt at a rebuild, im starting school and plan to make this truck my thesis, from what ive read so far this was the right place to start my search for information

 

I can I tell which tranny I have on my truck and could that help me figure out which engine I have

 

If it is automatic, then it is a C6. If it is a standard I would think it should be a NP435, and a c6 could of came behind a lot of engines.

 

its an automatic so I guess its a c6 which i guess is good news, now to figure out which engine im working with for sure