Hello, as the title says I'm trying to figure out what type of engine I have.

Here's the story, the original engine in my truck (1981 f150) was replaced a few years ago with approximately the same engine but there are some slight differences so I need to find exactly which engine it is. I need this because I am looking at replacing my exhaust and intake manifolds and my carb to get a bit more power out of my engine.

The reason I noticed is because I went to get new wires for the spark plugs and the ones I got for my engine from the store do not fit the engine that is in my truck.

Any ideas on where start my search for the identification number without pulling it apart? or any significant traits to look for to make the id?

thank you

 

Can you post up some pics? Take one of the fuel pump and one of the intake where the upper hose attaches.

 

351m and 400 have 8 bolt Valve Covers, the Upper Radiator hose goes into the block, the fuel pump bolts are vertical. 302 and 351w have 6 bolt Valve Covers, the Upper Radiator hose goes into the Intake Manifold, the fuel pump bolts are horizontal. Now there is one other thing if it has 6 bolt valve covers one way to tell the difference in a 302 and 351w is if you can get a socket on to the bottom bolt of the thermostat housing it is a 351w you can't do this on a 302 as the timing cover is in front of the bolt.

Hope this helps.

 

okay I have some pics. first off it is a straight 6.
the first pic is the fuel pump (right?)
the second and third pics are from the left and right side (respectively) of the the upper radiator hose connection to the motor
the fourth pic is the side of the engine. the valve cover is the part on top not the one on the side right?

if the valve cover is the one on top it is 8 bolt, and if it is the other then it is a 6 bolt

from what you guys are saying I think it is the 302. If I ordered some headers fit for my truck would it be a problem that it is a different model year engine than the stock one?

thank you

 

If it is a straight six it is the 300 which is the 4.9L

 

Yea that is definitely the 300 straight 6

 

I completely forgot about the 300 my mistake, I believe the only way a 300 can have a header is if it is the Industrial block, at least that is what LMC truck says..

 

how would I be able to determine if it is an industrial block?

my problem has been that every few years my exhaust manifold warps and I have to have it refaced which is a lot more money than a stronger header will cost, plus it would be nice to have a bit more power.

 

Nice post Mud Slayer, as it turns out, he has the 300. It would have been nice if he would have posted that on the get go.

 

There is a forum dedicated to nothing but Ford Inline 6 cylinders but I can't remember it off the top of my head. I used to have an industrial block 300 in an old pickup I had but can't remember the difference between the regular blocks and industrial, I think they were higher nickel content made for the higher RPM and slower moving big trucks, but don't hold me to it. Now there is also another mod you can do where it utilizes the 87-96 EFI manifolds so you can make dual exhaust, they are split to piece instead of one, if you go this option and the header option, you lose the heat stove under the carburetor, but they are both worth it IMO. The EFI manifolds will reduce back pressure some allowing a little more power. This is an excerpt from wikipedia.org about the industrial manifold:
And here is a link to another forum I'm on where a guy upgraded his 300:http://fullsizebronco.com/forum/show...andoned+bronco

Hope it helps.