Main bearing cap difference

[Idle_Mixture]

hi,
   just wondering if anyone can shed some light on this subject..i had played around for years with greys when younger not really taking a lot of notice(as ya do)..after 0  years absence i see now i have 2 differing sets of main caps in my possession..to put it simply..the 2 middle caps of one set has a thick ridge or gusset cast over the back and on the other set the 2 inner caps are basically just the curved flatish ones with the regular lip at the edge similar to the conrod caps..what gives there  ??? one motor is a 132 and the other a 138..was this just a normal factory component change/redesign/upgrade..is there a preference when rebuilding a grey? cheers chris

[Idle_Mixture]

oops.. ;D..doh..after 0 years absent should read 10 years sorry :P