I understand the 390 is basically a stroked 360? So would a 390 from a 1976 f-250 bolt up to a auto trans from a 1969 that had a 360?

I'm looking to go buy a the 76' f-250 with that 390, the guy said the motor is good. hoping to swap it into my 69' that lost a piston pin clip and now the block is junk.

 

Bell pattern is the same.

A 360 is a 390 with a 352 crank. (basically) Crank, rods and pistons are different, but the bore is the same.

Check that '76, it might be a 360 also. They sold more "390" stickers than 390s....

 

It'll fit so snuggly you will think it came from the factory. Can you say direct bolt up?

I would grab the left engine perch (stand) while you are at it, just in case you want to convert the power steering too.



John

 

I didnt see it mentioned, but is the f250 a auto ? if not the crank will have bushing in it. I hear it's not a good idea to swap them mid life, something about thrust bearing issues. But cant confirm that myself.

 

Good point.

No, the donor truck has a manual. Didn't think about that. It has a totally different crankshaft? You can't just bolt up a flex plate instead of a flywheel?

 

Here you go : 330, 352, 360, 361, 390, 391, 406, 410, 427, 428 all are the same family of engines and uses the same bell housing bolt pattern!

 

No sir, crank has always been the same in my experience. I believe he was referring to the pilot shaft bushing that slides into the back of the crank.

Also, all but two of my FE swaps were done with mid life engines and most were coming from automatic transmissions and all went into manual transmission work trucks. No thrust bearing problems but then again I baby my work trucks and rarely go over 2500-3000 rpm.

What always goes out on my mid life FE engine swaps are the heads. This is my own fault and I realized it was because I was heating up the top ears on the heads with the hot wrench to get the old exhaust manifold bolts to turn loose. I figured it was saving me having to pull the heads but what the heat was doing was messing up the valve seats. Finally, and I have done about 8 of the swaps at that point, I realized if the top bolts are stuck there is only one answer. (Probably only one answer in the long run anyway with these mid life FEs usually needing valve seats, valve job, exhaust bolt work, and head gaskets from rust build up) Pull the heads, have them checked for cracks, have all exhaust manifold bolt and threads removed-drilled-chased-taped-checked and fixed as needed, have hardened seats and a valve job done, have all 4 surfaces checked-cleaned-ground, and be done with it. Use good gaskets going back on. Also have them grind the exhaust manifolds and restud the ends and use BRASS nuts. Yes use manifolds not headers unless you just have to have that little bit more HP on an already kick a$$ engine? The manifolds will stay put and will make us old timers smile when we see them on your truck

Sorry to go on and on but I LOVE the FE family and the only ever follow up trouble is from the heads so do the head work in the front so you don't have to do it in the back.

Oh, and you will probably hear it a lot as this thread grows. The only way to know you have a 390 is to measure the stroke but even then these FEs are great FrankenMotors with 352 and 360 and 390 parts possible. Best way to know for sure is if you rebuilt it. But I know how it is to not be able to rebuild when you want to so just measure the stroke and pop it in your truck for now. And yes grab that driver side engine tower from the 76!
Mike.

 

Do a compression test on the 390 to make sure it is worth the trouble.

Interesting comment about the torch on the exhaust ears. Even when leaded fuel was available, seats and guides would wear out. Just like I keep filling the tank and it eventually winds up empty, or my hair isn't growing back and what's left is coming in white. Facts of life and physics, that's all.

 

I read somewhere the pilot bushing will come out easily using a press fit dowel/drift and packing the center with grease. Pack, and punch and out it comes. Never done it though. BOL