Hi All,

I finally registered on this site after searching and finding so much great information for my project. I am restoring a 1973 F100 XLT.

My truck has the 360/C6 combo in it and I have read that the mpg and the power of the 360 is not all that great, on the other hand I have read many good things about the 390's.

There is information on the web about converting my 360 to a 390 and that the only change to be made is crank and rods.

If this is the case, can i still use my old 360 pistons on the 390 rods rather than purchase a new set?

I realize that it would be simpler to just buy a 390 and put it in but i want to keep the truck as original as possible while improving performance.

Thanks!

 

Well the short answer is yes you only need the rods and pistons.
The long answer is more involved but truck engines have different pistons also.
The 360 will benefit greatly from just breathing better with a new set of headers and a intake manifold with a 4 bbl and maybe a new cam and will last forever.
If you are going to go to the time and expense of tearing the block down to build a 390 why not do it right while it's down with all the right parts which is a complete rotating assembly. And as long as it's down the heads should be done and on and on and ...........$$$$$$.
So it's not just a simple thing to execute although it is a simple theory.
Oh, and welcome to FTE.

 

Pull the 360, wrap it carefully and store it. Now drop in the 390. It'll be a lot easier (and probably cheaper) than swapping internals...

 

You need crank ,rods, and pistons . An aluminum 4 barrel manifold would be good since you have everything apart anyway . The existing exaust manifolds will do . But you need dual exaust . From that point , more preformance requires better lubrication and cooling (i.e. More fluid capacity , better fan , etc .) If you are going to build horsepower , you have to have a good foundation .
If you can find a machine shop that knows how to build an FE .
Good luck.

 

I live in vegas and had a hell of a time finding a shop that even knew what a FE was. I went out of state and got a reman for 2500 shipped. He opened up the correct oil ports mmachined and buiit it for the use it is going to get. Havent fired it yet but im not worried about it. Thas a hell of a lot cheaper than the one shop I found in town that would work on it. Just find one and drop it in. It will save you a ton of money

 

I converted my 360 to 390 specs. I would strongly recommend changing the pistons too. A big reason the 360's performance sucks is because of it's anemic compression ratio. For emissions reasons Ford dropped the compression on 360's by reducing the compression height of the pistons. If you pull your heads you'll see the pistons actually sit down in the bores by .100".
Use the 390 pistons that have, I believe, a compression height of 1.760" this will bring the piston up to a few thousandths below the deck.
Here's how mine turned out, I was going for a stock look so, unfortunately, no headers .