I had a 4L60E built up and the builder suggested just using the stock carrier but he did the sleeve and roller conversion to apperantly reduce friction/ extra mass in the trans. I'm not sure if this setup is capable of handling mre power.

The whole build up revolves around balancing and applying bearings to everything from what I can make out, am I being short changed due to the lack of hard parts?

 

Did he machine the stock parts for the bearings?
You do mean the reaction carrier right, not the reaction shell.

 

Sleeving the input drum will increase the HP level of the trans. There are many other tricks to the 4L60 to get it to hold power. Do you have a list of parts he is using? You can get on some sponsors website and check their list of parts to yours and see if you are getting short changed. But that still does not count for all the tricks to the 4L60.

Chris