Can I put a LS1 intake on my 5.3-327 using the 5.3 fuel rails and injectors and changing my water pump to a ls1 water pump for intake manifold clearance and not alter the ecu programming or having to change pullies or serpentine belts..?

 

The throttle body won't clear the truck alternator bracket. You can modify it and buy and relocation bracket for the idler pulley. . You will need car injectors and fuels rail set up or adaptors for the truck injectors. It's not to bad of a job just takes a little planning. There are step by step thread somewhere not I can't find it now.
I have a relocation bracket and Truck alternator bracket already modified for sale if you need one. PM me this your interested

 

You don't need a relocation bracket. You just have to mod the alternator bracket and then use a 2007 and newer truck water pump or a 2010 Camaro LS3 pump. Camaro pump will work better. The idler at the bottom right has since been removed as it was not needed.

 

Interesting , i havent seen it routed like that . Everyone seems to use the relocation bracket . Looks good like that . I ended up buying a ls1bracket to relocate the the alternator lower . I like the looks of it much better

 

What LS1MCSS said.