340 crank I.D.

[bizjetmech]

I've got three forged steel smallblock cranks. Bought them as a lot from a Chevy boy, was told that they were 340 cranks.

I have looked them over extensively; only one has a casting/forging number, which doesn't correspond to ANY crank I.D number in my reference material........one looks like it has had the counterweights turned down to lighten it. None of my references give any info on the physical differences between a 273, 318 and 340 forged cranks.

So......is there any way to identify these things? I've had to move these heavy ba$tards 4-5 times when relocating for new jobs/homes, and it's getting a little old. If they aren't worth screwing with, their next trip is to a recycling center (in fact, they are a big enough pain in the azz that they may go anyway).

 

[crackedback]

340's usually had the rod throws lightened with a rifle drilling. 273/318 are usually solid, no lightening in this area.

 

[retsud_043]

Do any of the cranks have holes drilled in the counterweights?

 

[Blownfish]

I'm not sure about the casting numbers on the 273 cranks but the 318 & 340 cranks are interchangeable, the only difference is most 318 cranks are cast. The 318 forged cranks came in older trucks and some 68-69 cars so if they are forged, they are worth keeping.

 

[green1]

Need pics; Forged /cast- you can tell by the marks. Measure the journals and throw.

 

[bizjetmech]

Don't know if anyone is still watching, but.......

Went out and took a closer look at these cranks............all three have a "rifle drilling"?/hole in the 1-2 and 7-8 rod journals. Batteries are dead in my digital mike, so I couldn't measure journal diameter. Since the are forged Small block Chrysler cranks with 6 bolt flanges, I'm eliminating the possibility that they are 360 cranks. (I have a 340 cast crank out of my old motor to help I.D.)

Anyone wanna buy them (cheap)?

Signed,

Recently laid-off bizjetmech that doesn't want to schlep these heavy mofos 1000 miles to my new job (when I find one.......).