i read a artcile somewhere on the net a while back i forget where but it basiclly said the 4L65-E was a ideal swap for the weaker 4L60-E since it can run off the 4L60 compture and...the houseing is the same just some internal parts are heavyer duty and has the same gear raitos as the 4L60 so..my qustion is if i ever blow a tranny like most blazers at 120ish k miles would it be a good idea to replace it with the MUCH BEEFIER 4L65 verson?

Captain i believe you requested some reading material.

http://superchevy.com/tech/0311sc_4l65e/

And yes according to that it should work.

http://en.wikipedia.org/wiki/GM_4L65-E_transmission
http://www.answers.com/topic/gm-4l60-e-transmission


Goto www.car-part.com and see if any 4l65-E's are available local to you.