Need help with a 340

[280bb0]

hey guys need your help working on a 1971 dodge challenger with a 1972 340 in it. went to change a leaking intake manafold and found the cam to have a good amount of wear so the tear down started, pulled the balancer off and found a crack near the key way the balancer says on it use for 340 with cast crank only. Problem is  how do I know what crank is really in it and 2 if it is a cast crank does anyone have a balancer I can buy please help this is turning into a night mare

[quapman]

Hopefully someone will post pics, but a cast crank has thin parting lines (where the two halves of the "mold" meet, and the steel crank will have a very thick section at the parting line.

I've seen 72 340's with both types of crank.

Sounds like the motor went bad due to modern oil with too little zinc or "ZDDP".

Everyone I talk to says to use Valvoline racing oil.

Have you posted a "parts wanted" ad?

Are you on cuda-challenger.com ??

[280bb0]

Thanks for the info Have not posted a part needed yet but will soon if anybody has a pic of the 2 types of crank that would be great!! 

[280bb0]

anyway to tell from where the balancer bolts???

[quapman]

anyway to tell from where the balancer bolts???

Not as far as I know.

[John_Kunkel]

Look at the engine serial number stamped in the front opf the block just below the cylinder head, if there is an E in the number it has a cast crank.

Late '72 (after 4-11-1972) and all '73 340's have cast cranks.

[280bb0]

Hey thanks for the info and yes it has the E

                 Brian