Originally Posted by OLDSter Ralph

I am not sure what the actual hardness of a connecting rods is. I'm sure they must be well over R"C" 30. But no one can quote a hardness number. If I recall correctly they are 1170 steel. I am thinking the connecting rods are about R"C" 45.
Trust me, I know R"C". Many years ago I machined punches and die pots that were R"C" 58-60. AISI A-2, A-9, O-1, D-2, D-5, M-2, T-15.
I am no longer working, so I don't have access to a Wilson Hardness tester.

Originally Posted by OLDSter Ralph

0.7% carbon.
Inconel is some tough stuff to machine. Annealed is not bad, but heat treated is way different. I've machined Inconel 718, 750, and 901. What kind of dies were they using it for ? Forming dies ? Bending dies ?

Originally Posted by Bernhard

Are you going to 4 bolt main cap the block?
BTR turbo DX Build
https://www.youtube.com/watch?v=s6dR0WCFRmA

Originally Posted by chadman

A two bolt main DX will handle a good amount of power especially if you have a good crank in it.

Originally Posted by CANADIANOLDS

factory rods are 1140 and will come in around 19 or 20 on the C

Originally Posted by OLDSter Ralph

Thanks for correcting me, I checked back on the GM Heritage site and it was listed 1140 steel for Olds connecting rods. I didn't see any hardness specs, however.
Hardness readings below 30 on the R"c" scale are usually not accurate. .40% carbon is above the transitional area between "case hardenable" and "full hardenable" steel.

Originally Posted by Tederra

Right, to me even 30 is too soft for rods and base off how many people say that's a weak point of the factory engine they're probably 30 lol. We use to normalize and air cool for like 35