It is supposedly from an early 70s Vette, and has been sitting for 15 years. The guy said he needed the crank then, and the block has been sitting ever since. It is a 2 bolt main, but from what I understand that is good because I can make it a splayed 4 bolt. I'm thinking about going to check it out. Anything I should look for that wouldn't be obvious?

Jason

 

Step 1:

FORGET THE "VETTE" BUSINESS

It's a block. No sublime properties magically waft up out of the fierglass and inbue themselves into the cast iron, endowing it with some sort of superior properties. Even if it had come "out of a Vette" (whether it was originally part of the motor installed by the factory in a Vette, or had spent part of its life in one, or was merely transported a short distance in one) makes no difference whatsoever. Not the slightest increase in value over a block that hadn't been in close contact with fiberglass.

Most of what you'd want to know isn't obvious to the naked eye. The one thing I'd be most leery of, based on this highly suspicious tale, is that the block has The Starter Problem; where the starter bolt holes are drilled too far away from the crank, and no amount of replacing the starter or shimming it will fix it. The next thing I'd watch out for would be The Lifter Bore Problem, where some or all of the lifters on one or both sides, don't point correctly at the cam. A block with that Problem will eat cams mercilessly.

Check the bore diameter, make sure it's not above 4.030". Look at bolt holes, make sure nothing is broken off or stripped, or has been tapped out to some larger-than-stock size.

And above all, DO NOT pay one penny more for it because of the "Vette" sucker line, than you would if it had come out of a 2-barrel Impala. It makes no diference.

 

So I need to take my starter and a dial caliper with me? What do I need to determine if it has The Lifter Bore Problem?

Are these issues for any block I look at?

Thanks,
Jason

 

To tell about the starter bolts, you'd need a crank (installed), a flywheel or flex plate, and the starter. That one is pretty hard to tell, looking at a naked block. I don't happen to have a measured dimension to compare it to. Easiest way to tell about that one, is the owner suspiciously selling a block that he's run, that looks perfect and undamaged and doesn't look like it really needed rebuilding; look for suspicious stories like "I needed the crank for something else", "it had a collapsed lifter", "a wrist pin was loose", etc. etc. etc., coming from someone who has subsequently built another motor to replace it. Ordinarily, if the block was good, an owner would have used it for something; if a seemingly good block sat in the garage while he spent money on other blocks to build otherwise similar motors, it's a good sign that there's something wrong with the block, the PO doesn't quite know what it is or doesn't want to deal with it, and just wants to send it down the road (make it somebody else's problem).

It's very difficult to spot the lifter bore issue, unless debris from a rolled cam lobe and munged lifter happened to damage the lifter bore. If you see a lifter bore with deep scratches or all chewed-up looking at the bottom next to the cam or has damage from a lifter that wouldn't come out because it had metal hanging off the sides, don't buy it.

Both of those issues were simple quality control failures during the block machining process; nothing more or less than that. It took the factory many many years to find and fix them. Any block between about 70 or 71 and about 80 is a potential victim. I'd guess probably a quarter or a third of all Chevy blocks, big and small and 6-cyl, made during that time frame, had these issues.

There are other, equally hard to spot malfunctions that a block can have. One of my favorites is where the bores either aren't perpendicular to the crank, but instead, point toward the front or the rear; or, they aren't directly over their crank journals, but again, toward the front or the rear of where they're supposed to be.

All of these are easier to detect in the owner, than in the block itself. I cannot emphasize strongly enough, a block that looks good to the eye that the owner refuses to run and is selling too cheap, is a giant red flag.

A micrometer would be great for the bore diameter.

 

You just made this whole excercise scary

The block is supposedly rusty for sitting for so long. That rust would probably hide a bunch of stuff I bet.

This guy allegedly sells vette parts and accesories. So a block that has been sitting for 15 years is probably one to pass on.

Am I better to go to a junkyard and take it out myself? The local one charges $200 if I return a core.

Jason

 

Yes, you can then get a 350 with a roller cam out of a later model. I used a 74 Nova engine to build my 355. I was lucky and had none of the above issues. But I do wish I had a roller cam. I also screwed up by using the stock 882 heads. Oh well, live and learn.

 

A used block like the one you're describing should be free, unless you happen to be a vette owner who's looking for matching #s.
Let that seller sucker someone else into paying for something that's basically worthless.

If it wasn't so expensive to ship, I'd sell you a freshly bored +.030 4 bolt for less than that.

 

well my guy that tows cars says he has a 400 engine that he'll deliver for $225. Considering that I would have to pay somebody to get it for me I think I may be right where I want to be. Now I have to find out about all the intricacies of the 400.

Is there a factory service manual that would help?

Can I use my same flywheel after it is freshened up, or do I have to replace it?

Jason

 

I can get blocks ready to go for $150, thats an engine ready for new internals, no machine work needed. Call around your local machine shops there should be plenty of doner blocks avalible.

Come to think of it I do have a vette engine sitting in the corner of the shop looks just like the rest except the oil pan is different (not unique).

 

I'd look into the 400. I want one but I cannot find one anywhere around here. Damn circle track guys take them all.