I used Pro Machine about a month ago to get my 5.3 ready for rebuild. They rock PERFECT customer Service!!Pro Machine in Murray did my 2F rebuild. I don't have a long history with them but they came highly recommended when i was searching. They we're great to work with and the the motor is still running without issue a few years later.
I've recently been told about summit machine. I don't know if they would also be worth a call
They do engine stuff?
I thought summit was mostly hardware like link arms and joints