Front beam differences

[buxtonbug]

Can any one give me a quick rundown on beam changes on early bays and how you can tell which is which.
Mines got prod date of jan 69 and trying to find out if a beam that available 2nd hand will fit. Any help much appreciated..... :|

 

[sparkywig]

Pre August '69 beams are the same bolt pattern as split beams. After August '69 (model year 1970) they went to the larger spacing.

 

[mattp]