273 Commando Identification?

[Bossanova5]

I picked up a grimy & tired Commando from a member on here. I used a scope to try to verify that it has the correct pistons. It appears to have only two valve relief depressions on the top of the pistons. The carbon buildup on the pistons (Especially the cylinders with low compression cylinders 4,6 & 8) is tremendous. I'm thinking it is a true Commando higher compression engine.
I found these faint numbers (Drivers side) stamped on the block.
Anyone know what these numbers mean?
It supposedly is the original engine from a 67 Barracuda.
It does have the commando valve covers, double point distributor and four-barrel manifold.
I apologize about the quality of the pictures.
Thanks in advance.

 

[junkyardhero]

look like commando pistons to me

sometimes a little acid can help reveal the numbers on a block when they're faint

 

[lkopaska]

Yep it's a commando!

 

[toolmanmike]

Yep. All dressed up and the right pistons.

 

[69FBCuda]

Solid or hydralic?

 

[toolmanmike]

Solid or hydralic?

67 should be solid. (you knew that)

 

[mvh]

Here's a cleaner piston to compare. This is a TRW .020 over replacement Commando piston from the 1980s (not the Egge version available now). Looks just like yours, I think.

 

[toolmanmike]

Here's a cleaner piston to compare. This is a TRW .020 over replacement Commando piston from the 1980s (not the Egge version available now). Looks just like yours, I think.

View attachment 1716367551

I don't see the drilled center in the op's photos. He will need to clean the piston top to make sure. All the pistons I have seen look close to the same with the stepped domes.

 

[perfacar]

sealed power and trw had that center hole in the top, OEM did not, just food for thought

 

[crazydog]

sealed power and trw had that center hole in the top, OEM did not, just food for thought

Pardon my ignorance, but what are the holes for? I do not recall ever seeing something like that before. Not that I have seen much.

 

[66fs]

I would assume for the manufacturing process for the forged pistons.

 

[toolmanmike]

Pardon my ignorance, but what are the holes for? I do not recall ever seeing something like that before. Not that I have seen much.

They are for a lathe center so they can be machined. (outside diameter turned and ring lands machined) The center is the cone shape you see on the right. The point of the center supports the piston as it spins in the lathe chuck.

 

[toolmanmike]

The Egge pistons have a centering hole as well but just a small one.

 

[mvh]

I always understood it was for spark plug clearance, due to the dome.

 

[perfacar]

it was for machining in a lathe. the plug sits way lower on piston. just food for thought

 

[perfacar]

i have a few sets of sealed power pistons for a 340, 2369P has same hole in the middle.

 

[cudamark]

What are the block casting numbers? Somehow I'm seeing this as a '67 318.

 

[mvh]

There wouldn't be any 67 LA 318s.

 

[cudamark]

Sure there is. All body styles including pickups had them, except for A- bodies.

 

[mvh]

There, you see, I'm always assuming we're talking about A-bodies.

 

[toolmanmike]

I always understood it was for spark plug clearance, due to the dome.

"I don't think so Tim"

 

[junkyardhero]

There, you see, I'm always assuming we're talking about A-bodies.

and here i thought you were the pedantic one in the relationship!

 

[toolmanmike]

The easiest thing to do is look at the number cast into the side of the block. 273=273 318=318