[pbhammes]

On the 66 3855962/396 block, how far can you bore them before running into trouble. I know this block has thicker walls, but now sure how far is tooooo far. A friend told me you can take the 962 block to 427ci?????????

 

[Ls6Convertible]

I have gone 4.281 on one of those[ .187 over !]....best to sonic check,they are super thick blocks

 

[Mike Feudo]

Unless there is a real serious reason to bore the block that much I would find something else that is already 4.250 bore. The block is too valuable to bore it to death unless you have to.

 

[pbhammes]

It is 60 over right now, and has some rust pitting in one cylinder. I'm not sure if .30 more will clean it up, plus I have a GM set of 427 11:1 pistons and 7/16" dimple rods to put in something. So that is why I was asking. If it is going to jeopordize that reliability of the engine, than I will not even consider it, but if it is no problem, then why not?????????

 

[SWHEATON]

Yes,that block was used for 396 & 427 from the factory in 66 & 67 due to thicker walls so you should be fine for a 427 bore.

 

[Tom Mobley]

like the other guys said, these things are really thick and were used for 427s also.

What you do need to watch out for is the rear cam bearing/rear cam journal. The cam must be grooved unless there's a groove in the block behind the rear cam bearing. this is not optional as several guys here can witness to. Some of the cam bearings have a shallow groove in them, it is not even close to enough.

unfortunately some machine shops have lost this knowledge due to the age of the parts involved and the fact that it was a two year deal to begin with.

 

[Ls6Convertible]

"Yes,that block was used for 396 & 427 from the factory in 66 & 67 due to thicker walls"..............#962 was never used as a factory 427 block

 

[pbhammes]

Thanks for the info.