So I'm doing a 5.3 swap into a '78 k10 and using the fuel pump assembly from the '01... We don't have great fuel pressure and wanted to replace the pump... Well, I go on to rock auto and order a new pump... When we remove the old assembly and pump, the new one doesn't look like the old one... The new pump is much larger, entirely different connectors and orifice locations, of course. The one that came in the original assembly is a Walbro. It has a part number, F10000256, and another number 29909-1, stamped on the side of the pump... I can not find a replacement... Every website out there has the larger pump listed as the replacement... I guess I will just buy an entire assembly to avoid anymore issues, but was wondering if anyone has had a similar issue?

I can post some pics of the two pumps if anyone is interested.

I am wondering if there was a recall with this pump and/or assembly... Every website out there has the larger pump listed as the replacement... It will not work with the stock assembly and I can not see GM using multiple pumps and/or assemblies in their full sized truck line... It was removed from a stock 2001 Z71...

 

or someone took the good pump out, and put that in to get rid of it

 

Why not just buy a $95 walbro 255 and put in there?