crank & piston ID

[nixrsix]

Aloha!
I'm trying to ID pistons and crank on a mystery 340 motor I bought. The pistons are flattop w/ 4 valve relief. It came with a lower blower intake manifold, so I'm guessing this engine was built for lower compression? I'm still learning, so any help would be greatly appreciated. Mahalo -N

 

[pishta]

rods look stock with a nice milled balance pad.. pistons look stock too, maybe Badger if not stock? 4 valve reliefs usually mean its a low line piston.

 

[brian6pac]

Definitely cast piston would not run with a blower

 

[nixrsix]

I have a feeling previous owner built a stock lower end for a blower or possibly a stock motor with lower compression something.Ugh. I want no blower, just a well breathing na motor. It looks like pistons/rods need changed, I want forged. Do any of the crank stamps ID what it is?

 

[nixrsix]

It looks like a forged steel crank to me, am I right though?

 

[nm9stheham]

Crank looks forged as you think. Those balance pads sure look different, almost like they are added on....???

Pistons look to be cast as said. The cross-hatching that can be seen in one pix under the crown is common on UEMP cast pistons, so these may be Slivolite 1267's which have 4 eyebrows, and which are kind of a medium low compression piston. They are not the same as the super low compression late production 340 pistons, and which sat .070-.080" down in the hole at TDC. Look to see if the number '1267' is cast in one of the skirts, surrounded by a circle of dots.

 

[Max1196]

Crank is forged, rods are stock, someone was talented when it came to the balance pad weight matching, and the pistons are cast but look like replacements.