Projects How bad is this really?

I need an opinion(s). I think I already know the answer but here I go. I have a 66 C10 pickup that I've been working on and it's time to address the engine. It's got a 283 with a little over 100K miles and is well worn. A leakdown check showed average cylinder pressure to be around 55 lbs with highest reading of 80 and a low of 35. It's a heavy oil user and I expected to hear air blowing through the valve stems, exhaust, carburetor and oil fill tube but the one that really worried me was when the radiator gurgled on #4 cylinder. So lets skip ahead to this weekend when I pulled the engine out and started the teardown and I find one headbolt (#7) that came out hard all the way with an air ratchet and the bottom half inch of it was rusted pretty bad. I don't think this engine has been apart before and I just don't think my radiator gurgle was from a head gasket issue. I strongly suspect a cracked head (power pak heads) The rusty head bolt and suspected crack are on opposite sides of the engine so I don't think they are related. This is from a running daily driver.

My question is this. Does finding a head bolt like that mean something bad or are there other causes? I don't want to take this to the machine shop just to have them tell me it's junk. My goal was to keep the engine original to the truck but I'm finding things that worry me and it's starting to look like this might not be practical. I know a crate motor is my best bet but I was really hoping to do this rebuild. Thoughts?

 

The bolts go into the water jackets , that's why they need sealant when installing.

 

I don't really have a lot of specific info, but I can make some generalizations. I've worked on those motors in both a dealership setting and building race cars in the 60's and 70's with basic 283 engines as the starting point. They just don't have any chronic head cracking or head gasket issues. You may have a rare crack between the intake and exhaust seats, but that was really the only crack area. You could in fact have a borderline head gasket after all these years which would give you some of the radiator gurgle. Look carefully at gasket area between cylinders. Even if not clearly burnt thru, you may see a visual difference which denotes poor crush and/or poor torque.
The rusty head bolt is kind of a head scratcher, but you could have had casting slag/junk down in the bolt hole ever since the engine was built. This is why engine blueprint guys talk about cleaning way down in the bolt holes and running a tap down in all the holes prior to head installation. It was not uncommon to think that you had good torque on a bolt, only to find later with a rebuild gasket failure, that the head bolt was bottoming in the hole.
If the engine lasted this long, it is well "seasoned" and would be a good rebuild candidate, if the basics can be sorted out.

Don't put yourself in a position of "needing" a crate motor based on problems that may not be all that big.

 

Yes.....yes.....I almost forgot in my post. Every engine I ever built included dipping the threaded portion of the head bolt in a can of Permatex before putting bolt in the hole

 

You mean you want to rebuild this engine and put it back in, but you don'r want to have any work done at a machine shop? Not even a magnaflux?

 

No I don't mean that at all. I just want to avoid taking an engine that has obvious big problems to a machine shop and wasting my money that's all.

 

Look at the head gasket around #4, is it thin?

The rusty head bolt thing is common on Chevys that had poor cooling system maintenance. Hopefully you didn't screw up the threads in the block when you removed it. If you did, you can get a thread insert in the hole without too much trouble, most likely. But they do have to seal coolant, so take a good look at the bolt hole.

Sounds like a normal old wore out chevy motor, to me. They usually turn out fine with some money and attention thrown at them

 

Most engine builders have a flat charge to check out an engine. This includes a hot tanking and examination.

The more work you do, the cheaper it gets. Mark all the rods and caps, main caps too. Try not to gouge the crank when you take the pistons and rods out.

 

All good advice and if you really want to keep that block and heads pay the machine shop to check them out first. If the shop says they are OK and you later find a problem then they should stand good for it. There is no shortage of Chevy engines so it won't be hard to find a good core to build. Most aftermarket blocks like Dart or Merlin use blind holes that don't go into water so you don't worry about the threads rotting away. You do have to be careful about using a bolt that is too long and bottoms out in the hole.