Need an ID on these 340 pistons

[RAT ROD AL]

Have a nice set of 340 +.030 pistons. Forged, Domed.. .984 pins
But no #s or other markings to ID these. Any idea how to tell manufacturers and comp ratio ?
Thanks for all information.

 

[ch1ll]

That's a good mystery, look like nice pistons other than having no coatings.

 

[33IMP]

My guess? (Note, GUESS!)
TRW/Speed pro with some of the dome milled down
Maybe why there's no i.d.

 

[JDMopar]

I think I remember the CR being 12.5-1 and they are forged. They look to be too modern of a piston to be old TRW's. They have 1/16 top and second ring grooves. Those would be a good match for some nice H beam rods....lol.

 

[RustyRatRod]

My guess? (Note, GUESS!)
TRW/Speed pro with some of the dome milled down
Maybe why there's no i.d.

I would go along with that were it not for one thing. The insides of the pistons are much smoother and more finished than the old TRW and Speed Pros. These look like a more high end piston.

 

[junkyardhero]

i'll take a flyer and say early Ross or mayyyybe Probe? possibly diamond?

 

[RustyRatRod]

i'll take a flyer and say early Ross or mayyyybe Probe? possibly diamond?

I'd maybe even say Arias. I have an NOS set of 351C Arias pistons and they look similar on the bottom.

 

[junkyardhero]

I'd maybe even say Arias. I have an NOS set of 351C Arias pistons and they look similar on the bottom.

that's a solid guess. their finish was generally very nice.

i'd say wiseco but i'm guessing there's no W on the skirt... but... when did they start adding that? *eyebrows*

 

[RustyRatRod]

that's a solid guess. their finish was generally very nice.

i'd say wiseco but i'm guessing there's no W on the skirt... but... when did they start adding that? *eyebrows*

You got me by the short hairs.

 

[junkyardhero]

You got me by the short hairs.

ew. no thanks!

 

[33IMP]

The old Arias and Ross that I've had had a rib around them below the pin, missing on those.
And 2295s (domed 440 trw's) had 1/16 rings 50 years ago.So did the 340 version.
I'm NOT saying they are trw's, the bottoms inside do look awfully nice, but they look more like trw's than Arias or Ross to me.
Either way, cr is a guess, with a lot of other factors determining the actual number. But low eleven to low twelves would be my guess.

 

[RAT ROD AL]

I think I remember the CR being 12.5-1 and they are forged. They look to be too modern of a piston to be old TRW's. They have 1/16 top and second ring grooves. Those would be a good match for some nice H beam rods....lol.

These are the pistons we got from Steve, on the H beam rods. I'll ask him if he remembers what the heck they are.

 

[RAT ROD AL]

@SBeeMan any Idea what these pistons are ?

 

[SBeeMan]

I don't know who made them. I was told they were 12.5 to 1 with closed chamber heads.
As far as the rods...stock stroke 340

 

[RAT ROD AL]

I don't know who made them. I was told they were 12.5 to 1 with closed chamber heads.
As far as the rods...stock stroke 340

Thanks for reply, Steve

 

[TT5.9mag]

I have a 12.5:1 set of arias pistons from around 2000 and they are very, very nice, and are marked.

 

[oldkimmer]

Looks like their gas ported or what ever they call it when the holes are in the ring lands. Kim

 

[MOPAROFFICIAL]

Ross or diamond