Hello to everyone here. I have been a lurker here for sometime. Lots of great info.
I decided to keep my 03 Sub and just do some minor work on it versus getting a new truck. I imagine there are several builds on here that started just like that. After having the motor pulled yesterday and discovering the cam bearings are locked onto the cam and have eaten away the block. I realized I need a new block. The reason the motor was pulled in the first place was no oil pressure at idle. The shop that is doing the work has a very nice, shiny aluminum LS6 block on the floor right now.
I already have a new cam, springs, retainers, shorty headers for the 5.3. Nothing major, this is a daily driver that sees lots of highway travel between Texas and Colorado. Parts are Comp Cam 54-452-11 (212/216@.050 520/524 115 lsa) 918 springs and steel retainers.
The real question is can I use the 5.3 heads with the LS6 or will my compression go through the roof with the smaller chambers? Stock 5.3 chambers being 61cc. I don't really want to spend the money on new heads. I am guessing I can drop some of the compression with dished pistons. There seems to be lots of talk of doing just this on the corvette forums for the added compression, but I want to run cheap gas and be able to run the motor for 20 hours straight up and down mountain roads.
I hope this is enough info.