poly crank shaft

[cudaman51]

i need a 340 crank shaft and am not doing well, i know where i can get one from a 66 poly 318 is that a useable crank shaft

 

[67Dart273]

I don't know but if you want an automatic that will have the small crank snout register "I bet"

 

[AJ/FormS]

At least its steel, fits in the block, and accepts the rods.It will be balanced for the 318 slugs though. With a bit of work/cash it should work.
Doesnt Mopar Performance have fairly affordable 3.31stroke cranks?
Im guessing your crank is "beyond repair"?
Might be worth looking into a stroker kit though, for a few more dollars.

 

[krazykuda]

Might be worth looking into a stroker kit though, for a few more dollars.

Why go stroker when all you need is a crank??

Stroker will need other new parts to work with it, and balancing...

Why go through all that when all you need is a crank and go....?

 

[AJ/FormS]

Well I was thinking, by the time you purchase and make that poly crank work, Youve got a good down payment on a kit.One time, a kit appeared here on FABO for $1000.
76 cubes for a G, is kindof a no brainer for me.Yeah I know theres incidentals.
I was just throwing a seed out there. Notice I tagged it on at the end of the post,and prefaced it by saying "might be worth looking into", as opposed to forcing my opinion on the OP.

 

[RustyRatRod]

The crank should all but fall in almost unmodified. Plenty of people have built the 318 poly into a 402 with the MP 4" crank and they bolt right in.

The only point of contention might be what Del is talking about. He's a wise old owl and you should research that. It's nothing that cannot be overcome, though.

 

[C130 Chief]

The poly crank will physically interchange BUT as mentioned above, the register will be smaller, the bolt pattern may not be the same, and being forged, it will be much heavier.

 

[perfacar]

the register can be bored out in a lathe to 727 snout dim. the flywheel bolt pattern is same, years ago, mopar wanted you to use the 318-3 truck crank in the 273 and 340 for racing, since it was chem hardened. I've done 3 of those registers in a lathe!!! sad to say weight is about the same as a 340.

 

[oldkimmer]

.....Don't quate me on this but I seem to remember this from years ago.....From my experience 66-67 poly cranks have the same registar.......the rod throws r too narrow and u have to machine them wider to have acceptable rod side clearance.....kim........

 

[skrews]

the register can be bored out in a lathe to 727 snout dim. the flywheel bolt pattern is same, years ago, mopar wanted you to use the 318-3 truck crank in the 273 and 340 for racing, since it was chem hardened. I've done 3 of those registers in a lathe!!! sad to say weight is about the same as a 340.

This.

 

[RustyRatRod]

It works fine. Read.

http://www.allpar.com/mopar/318.html

 

[cudaman51]

thanks everyone for the replys