have a 390 and a 4speed i am going to buy to put in my 71 f100. i have a 360 and a 4 speed in it now, i know they are almost identical but i was wondering if there is anything i need to know. thanks

 

Like what? :)

Alvin in AZ

 

71, More likely than not, the engine that you are buying is a 360 also. There just weren't that many 390s put in trucks.

Get a piece of 14ga. white house wire about 6-8in. long and poke it through one of the front spark plug holes. With a Sharpie resting on the manifold, have a friend rotate the engine a couple rounds with a ratchet and measure the length of the mark left. Pull coil wire so that it will not fire.

Report the measurement back here, we'll tell you if it's a 360 or 390.



John

 

ok, ill check on that. My plan is to take this other engine and trans and put it in the truck temporarily while I rebuild and throw some performance parts in my original engine. the mechanic i am buying the engine from guarentees the engine and will intall it for me. and i am picking it up for $400.

 

May I suggest you sweeten the engine that you are purchasing.

You might be happy with the results.



John

 

i stuck a doll rod down the cylinder and if I measured right, i got about 3-3/4 inches. is that about right for a 390.

I saw the engine today, it looked fairly clean, the oil looked good, and i was able to turn it over with my hands.

Yeah I am going to spice it up a little with a carb and headers that i already have, but i dont want to put to much into it because i plan on making the 360 that is coming out into a hot 390 or a 410

 

That is about right for the 390. Sounds like a good replacement.




John

 

i didnt think of it at first, but i have been looking in my shop books, and i think that engine is a 391.

I am saying this because it has the big oil bath air cleaner, the different looking manifolds, and the hard line from the distributer to the carb.

and i dont want a 391 because i dont think it will fit and the lower compression, torque, and horsepower.

 

The 391 is a FT engine out of a fairly large truck, rather than a FE from a car or pickup.

Check the photos here to see if you see any manifolds like you saw.
FE Factory Exhaust Manifolds



John

 

I was given a 361FT and the front half of a C700.
Still haven't done anything with it. :/

On the FE/FT forum a guy posted a graph showing the 361FT
had less horsepower and torque etc than a 352FE or 360FE.

Funny thing was, that's how everyone interpreted it that way,
except for me. ;)

What I saw was -if- you limited the RPM's to 3500 (the way I drive!)
-then- in that portion of the band the 361FT kicked both the FE's butts
in both torque and horsepower.

You know, the engine is most efficient at it's peak torque RPM.

So, just how high do you rev your engine anyway? ;)

Alvin in AZ

 

http://home.windstream.net/bsprowl/E...361T391Tc1.jpg
Those look like my 361FT's manifolds. :)
Look pretty good, don't they? :)
For a truck. For low end torque.

And this is what my pickup has on it...
http://home.windstream.net/bsprowl/E...x/th_FELog.jpg

The 391FT will have engine mount provisions on the steel timing chain cover.

In the old days a steel crank from an FT was prized and modified to work in
an FE but those days seem to be gone, machining costs etc are higher than
aftermarket stuff that's ready to go.

Alvin in AZ

 

i talked to the mechanic and he assured me that it came out of a 66' f100 and went into a 70s 1 ton and then scrapped the truck. He told me that it would fit and that it ran good, he even guarenteed it.

Really though, it is just a cheap temporary engine until it can build my 360 that i am pullin out.

 

Regardless of what he says, the 352 was the only V8 offered in a 66 pickup. It will fit as the FEs are the same on the outside. Hard to say what someone else might have swapped in over the years. So if you feel good about it go with it.



John

 

got the engine home today, pulled the trans off and put it on a stand. It is definetly a 390, the tag on the valve cover says so and the mechanic said it came out of a76' now, but i looked up the stroke for the 390 and as you said earlier john, it measured about 3.75 inches.

The plan is to freshen it up a little and paint it.

 

Hope it works well for you. You may like it enough to keep it.



John