Does a 73 the crankshaft pully on a cast crank 340 have a different bolt pattern?

[wawarnick]

Good day. I am getting back into working on my Dart after several years. I bought a 1973 340 and rebuilt it. I have a couple of crank pulleys, one from a 67 318 with 2 grooves. The pulley that came with the engine has 4 pulleys. The all but one hole will line up on the 2 groove no matter how I spin the thing around. I didn't look closely when I took it apart, but it appears that someone hogged out one of the holes to bolt it one. Did the cast crank 340's have a different bolt pattern for the crank pulleys? Thanks in advance/

 

[JDMopar]

The bolt pattern changed in 1970, when the aluminum water pumps with the longer snout and passenger side inlet started. It's not your 73 balancer that is different. It has the standard 70 and up pattern. Your best bet would be to find a later set of pulleys in the configuration that you need. Bouchillon Performance in SC sells every kind of reproduction Mopar pulley you can think of.

Home - Bouchillon Performance Engineering

Bouchillon Performance Engineering - Specializing in Mopar geniune and custom engineered parts and accessories located in the low country of South Carolina.

www.bouchillonperformance.com

 

[wawarnick]

Thank you

 

[tonysrt]

Chrysler used to do that for some reason, have a different offset bolt pattern on the pulleys. When you encounter that, the answer was to hog the offset hole to make it fit on later crank dampers.

 

[MoparMike1974]

I have seen pulleys with one oblong hole like that from the factory. It was clearly stamped and not hogged out.

 

[cudamark]

The change was in 1972. '71 and older used the one staggered hole so the pulley will only mount one way. The '72 and newer balancers/pulleys used an even pattern so the pulley can mount any of 6 ways. Nothing wrong with slotting the one hole to make any combo work......in fact.....most of the later replacement pulleys you got from Mother Mopar have the slot built in.

 

[67Dart273]

The bolt pattern changed in 1970, when the aluminum water pumps with the longer snout and passenger side inlet started. It's not your 73 balancer that is different. It has the standard 70 and up pattern. Your best bet would be to find a later set of pulleys in the configuration that you need. Bouchillon Performance in SC sells every kind of reproduction Mopar pulley you can think of.

Home - Bouchillon Performance Engineering

Bouchillon Performance Engineering - Specializing in Mopar geniune and custom engineered parts and accessories located in the low country of South Carolina.

www.bouchillonperformance.com

No need at all. If the pulley stack lines up and works otherwise, just file out the odd hole and go with it Back in the day (before we had the internet) I used to just leave one out