Which FelPro one piece oil pan gasket

Anybody know the difference between the FelPro oil pan gaskets OS34600R and OS34507R? Both are listed for late model 460 but is will they both work on my 72 block? I used the M-6017-a460 last time but it's not available locally. Thanks.

Tree man:
I believe the OS34600-R gasket is for early applications, all 1/4" holes, except the corners which are 5/16". The OS34507-R is for late applications all holes are 1/4". The OS34600-R can be used for either application, that's what I did - worked fine.

Wayne (SAWDOFF) Pearce

Perfect. Thanks.

Wayne Pearce wrote:Tree man:
  I believe the OS34600-R gasket is for early applications, all 1/4" holes, except the corners which are 5/16".  The OS34507-R is for late applications all holes are 1/4".  The OS34600-R can be used for either application, that's what I did - worked fine.

  Wayne (SAWDOFF) Pearce

Damn those are only $10 more then the regular multipiece one I just bought. I'd never seen the 1 pc.

They came on the last generation 460's in the trucks. 1990's