The following photo's are from the engine i have just pulled down, these are the main caps and are numbered 1 through 4 left to right
Notice the increased wear the further you get away from the oil pump, the conrod bearings have this same wear like these further away from oil pump worse wear.
LEFT TO RIGHT 1 TO 4
#1 AN 2
#3 AN 4
This is what i am trying to help prevent by running another external gallery around the outside or the block and into the main bearing feed gallery in the rear plate.
I'd really like to hear from someone who has done a performance build on a v6 ecotec and see what they had done if anything, i do agree that this may not be a real bad issue but all of the v6's i have seen that have spun bearings have all done it on either #5 or#6 all the way at the back of the engine.
I am loading the engine up more than it is done on its stock form by turbo charging it and just dont want to have any issues with it later on, i cant really afford to be rebuilding all the time or replacing engines.
Maybe i am reading too far into it and worrying for nothing, is there a high volume oil pump available for these.