I'm looking for a 390 for my 76 f150 and was wondering what to expect them to be worth. I've found a 73 390 for $250, and a 68 390 with a c6 for $450. Do these prices sound about right?

 

It depends on your location, but those don't sound outta line at all.

 

Ya, got mine with the 4 speed for $300.

 

Be careful. I found them from 250 up to $900.00. Many are old junk. I had three sent to the machineshop and all three were cracked. You couldn't see the cracks nor did they leak. All had tons of sealer dumped into them.
I finally found what I was told was a good 352. Yep it was cracked as well but the machine shop said the crack was small enough to repair.
All the ones I found had paint covering the cracks. I have a fortune in magnafluxing but I also think I have a good block capable of going back into service.

All of the above is based on I want a new as can be engine.
In short. I wouldn't pay over $200.00 and I would only give 100 down and then have it checked out. No cracks and I would pay the balance.

I want a new as can be 390 for in my truck so I guess I am way to particular. My 74 is going back into full service towing my goose neck trailer loaded with tractor and equipment as well as my 12000lb house boat.

The big thing I was warned of was the valve seats. The heads that haven't had hardened seats installed will destroy themselves if you use non lead gas and drive the truck. Head work can easily hit $500.00 for both heads. Becareful who does the head work. Cheap guide knurling is a only a 20,000 mile fix at best. If you want a sit under the shade tree truck no problem any old painted block will work.

 

Are cracked blocks common of the FE engines?

 

They seem to be for me, the one I took out of my truck to have rebuilt, the machine shop found a small, non-repairable crack on one of the water jackets on the transmission side of the block.

Since I was needing a block, I ended up buying one from the machine shop, even it was cracked but had been pinned and repaired.