5.3Caprice

iTrader: (3)

I bought an '05 2WD 4.3 extended cab with a knocking engine. Then I got a smashed '03 5.3 4x4 as a donor vehicle. Sounded easy enough...

I didn't realize that the fuel systems had changed until I pulled out the 4.3 yesterday. I already licensed the donor trucks PCM with HPTuners and deleted VATS before I pulled the engine.

My plan is to use the '03 PCM in the '05. Should I swap the '03 (return) fuel system over to the '05 (returnless)?

Any info is greatly appreciated. I've been reading a lot about it and I'm still not 100% sure which way I should go.

SLOPONY

I went return style in my swap truck. Truck was an 01 and the donor tahoe was an 01. I also changed over to an in line pump, and rear mounted fuel cell. I personally like return style. I just feel like I am avoiding any dead head fuel issues.

Atomic

iTrader: (42)

You can use either, just depends where you want the regulator. No reason not to go.return since your fuel tank is set up for it.

5.3Caprice

iTrader: (3)

Just an update. I swapped the complete '03 fuel system (tank, pump lines, evap, purge) to the '05 body. It was a lot of labor but should keep PCM tuning simple. Truck fired right up and runs great.