340 engine bore questions

[ralley72]

How much is to much to bore a 1972 340 block? I have a 72 340 block that came with 60 over pistons. A rough mic was 4.09 on most of the bores. Is this block only good for a end table?

Mike

[John_Kunkel]

Only an ultrasonic thickness test can answer that question.

[sccachallenger]

Only an ultrasonic thickness test can answer that question.

This, many have been surprised how much there is there.
Hensley Racing reportedly has bored 318 blocks to 4"
This is .090" over!
Let us know what you find.

[Challenger340]

How much is to much to bore a 1972 340 block? I have a 72 340 block that came with 60 over pistons. A rough mic was 4.09 on most of the bores. Is this block only good for a end table?

Mike

As mentioned, get the block sonic tested, go from there.

.060" +.005" oversize Pistons are available from Diamond and others, we do it all the time, pricey, but just say'in it ain't dead.

[BSB67]

How much is to much to bore a 1972 340 block? I have a 72 340 block that came with 60 over pistons. A rough mic was 4.09 on most of the bores. Is this block only good for a end table?

Mike

As mentioned, get the block sonic tested, go from there.

.060" +.005" oversize Pistons are available from Diamond and others, we do it all the time, pricey, but just say'in it ain't dead.

This.  If a ring set is available at the closest final bore diameter, a piston can be made.  Like Bob said, probably 0.060 + 0.005.