Hi Guys .. I Want To Change My 2004 5.3l Silverado From A Returnless Fuel System To A Return Style System . So Will The Fuel Pump Assembly From A 2003 Fit Onto A 2004 .i Know I'll Have To Put In A Return Line & A Couple Of Other Mods ..but I'd Just Like To Know If The Assemblies On Top Of The Tanks Are The Same ..thanks

Or If Someone Else Has Done This Before . Please Point Me In The Right Direction ..

 

I bet they are the same tank. See if you can find a complete bucket assembly off ebay or something. I bought one a few years back and it made the conversion pretty easy. Then you'd need the rails (which are easy to find) and a return line. Make the needed adjustments to the tune and you should be good to go.