The block has already been bored .040". The cylinder walls look good. But I want to start with a block that's been freshly bored and torque plate honed. I don't know if this block can be bored to .060" or not. I'll have to take it to my machinist and see what he says.

I'm not going to use the crank.......and I'm glad I wasn't planning to. It's already been turned .020". Both the journals and the bearings look horrible. They are scored/grooved/gouged terribly. I've never seen crank and crank bearings torn up as bad as these are on an engine that didn't spin a bearing.

The rods and rod bearings are just as bad as the crank and crank bearings. Same with the cam bearings.

I was hoping the engine wasn't touched. It has been. I really wanted to use the block. I don't think I'm going to be able too though!

 

i have been taught that 30 over is the best place to stop on a 350. thats not to say u cant go 40 and be ok.

 

I think a lot depends on what casting the 350 is,I've heard the Goodwrench replacement engines cast in Mexico are so bad that most good engine re-builders won't touch them at all.
On the other hand a friend of mine had a high nickle first gen LT1 out of a '70 Z28 in his '55 Cameo pickup that was bored .060 over with 11.1 compression and it ran great,really really great! lol.

 

My casting number is 3970010.

 

Is it a 4 bolt main, or 2 bolt? 3970010 is a good casting as it has a high nickel content. If it's a 4 bolt I would see what the machinist says about boring it .060 over. If it's a 2 bolt I would just find a virgin 3970010 4 bolt block.

 

Lifted this from another site......
3970010....302.....69....4 bolt main...Z-28 Camaro
3970010....327.....69....2 bolt main ...Trucks and industrial
3970010....350...69-80...2 or 4 bolt main

There is a serial number stamped on a little pad above the water pump next to one of the cylinder heads. Post that and somebody can give you more information about your engine.

Usually this pad is in front of the passenger side head on the top deck of the block,it will tell what the motor came out of.

 

My block has two bolt mains. I'm going to pretty much duplicate GM Performance Parts 350 HO engine. It makes 330 HP and 380 FT. LBS. of torque. A two bolt block will be fine for what I'm going to use it for.

I talked to my machinist today. He is going to sonic test the cylinders to see how thick they are. He said some blocks are thick enough to be safely bored .060" over and some aren't. I'll have to drop it off to him so he can check it out and go from there.

I hope I can use it. All I want to use is the block, main caps, harmonic balancer and the flex plate.

We're throwing out the crank, rods and pistons. I'm going to hang onto the heads until I get the Vortec heads. Then I'll put them in the paper for a $1 (can't put things in for free or I would). Someone might be looking for a set of heads for an old work truck or something. These heads would make good cores.

 

by your sig im assuming ur in ny so im probly to far away for it to be worth it. i have a bare block from a 69 1/2 ton truck, 350 4bolt so i saved it, been it the shop forever. i think the caps are still on it.

 

For your needs, a 2 bolt will do you just fine.
The 3970010 was a widely used block casting, and does not automatically mean high nickel content. Whether or not it's a 2 or 4 bolt main has no bearing (no pun intended) on the integrity of the cylinder bore. Final block machining was performed after the block was cast.
As far as the 010/020 high tin/high nickel content block markings under the timing chain cover, I have read anything from saying that is what it stands for, to it only refers to the main caps, to it's a myth and that's not what the numbers mean at all. I would like to see some documentation (if anybody has a source) FROM GM stating the true facts or fictions about the cast iron's content. Anything else is just opinions and speculations, and only a metallurgical test can confirm the claim.
But still, since the largest benefit of a higher nickel content would be durability and longevity of the cylinder wall, it wouldn't make much of a difference on a street engine unless you wanted it to last mega miles, or if you have an ultra thin wall after an overbore.

 

I'm pretty sure my block has a large 010 inside the timing cover. I have no idea what that means. I just hope my cylinder walls are thick enough to be bored to .060". If not, my project is more then likely done for now, maybe for good.