TBSS Intake swap.
Trailblazer SS intake swap to a gen 3, 5.3L truck. The swap of the two intake manifold was quite easy and simple, just make sure to go by the torque spec diagram in the article menu. There is a pattern to follow to make sure not to disrupt the intake gasket seal. The TBSS fuel rail does not have a return fitting. You can get around this by tig welding an “AN” fitting to the other side of the fuel rail, or just buy a C5 corvette fuel filter / pressure regulator. It connects the forward and return lines to one fuel line that connects to the manifold.
If you plan to use the fuel injectors that came with the TBSS you will also need adapters to plug into EV6 injectors. Its a simple plug and play adapter, you can even cut them and wire them in for a cleaner factory look, add a nice looking wire loom for a nicer look.
For the throttle body, the way I see it there are two options. My truck is a 2003 GMC sierra 1500 SLE. It is drive by wire (DBW) meaning it is electronic and not cable drive. So option 1. get a ICT billet 4 bolt to 3 bolt adapter. You will be able yo use your old throttle body with no issues, even with a cold air intake there are no clearance issues with the fan shroud. Option 2. get a X-LINK harness adapter witch allows you to use a bigger 4 bolt TB with a 6 pin connector and it plugs right into your existing harness.
Fairly simple, easy to do, good luck and have fun.
I will post links below to the C5 filter and TB adaptor.