Quick truck intake question
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Teching In
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Quick truck intake question I have a 2004 Trailblazer DBW complete intake (complete engine actually). I want to make it DBC for a swap. Can I just use a stock replacement GM or boneyard DBC throttle body off a 2000, 2001 etc? Will it bolt right up and be good or is that a no go for some reason.
Thank you -
Thank you -
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
The DBC TB will bolt right on.
Your engine is the LM4, an aluminum block 5.3 that came only in the Trailblazer and its other GM siblings.
Same as the LM7 except for block material.
Your engine is the LM4, an aluminum block 5.3 that came only in the Trailblazer and its other GM siblings.
Same as the LM7 except for block material.
Last edited by G Atsma; Jun 10, 2023 at 07:54 PM.
Thread Starter
Teching In
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Thank you. Do people usually continue to use the original 20 year fuel old rails or is it recommended to change them (Im talking strictly from a safety/failure standpoint)?
It looks like my intake has the return style rail set up. I have not decided if I'm going return or return less yet (simply for the fact that I have not researched it enough yet)..
It looks like my intake has the return style rail set up. I have not decided if I'm going return or return less yet (simply for the fact that I have not researched it enough yet)..
TECH Addict
Joined: Oct 2016
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From: PDX-OR-USA
RE the fuel rail, I just cleaned mine up and used it, no significant corrosion and it fits..
Just my .02 bucks worth. personnal observations..
I personally not a fan of non return systems.
Return helps keep the pump cooler.
It will purge fuel bubbles out of the supply line.
I also dont use an external fuel pump. I have lost count of the DNF cars I've toed off track with burnt out
external pumps, The pump needs to move typically at lest 10% of its capacity continuously,
if it starts to dead head the pump motor heats up and then the wiring and relays which raises the load
and it spirals worse and worse. (You can test this just sitting with the engine idling. IR gun, and a fuel
pressure port on the rail and at the supply port on the pump.
I know if you'r going to big enough power, yea, you'r going to maybe need a pump that can't be internal.
At that point a GOOD regulator that lets the return happen without causing too much back-pressure to
the pump and still provides the pressure return relief is a must have. Its not much different than sizing a
wastegate, the regulator is a major player in the system.
Checking both rail pressure AND pump head pressure is important, if the pump goes in to internal bypass it
cavitates the fuel and heats both the fuel and the pump up.
Just my .02 bucks worth. personnal observations..
I personally not a fan of non return systems.
Return helps keep the pump cooler.
It will purge fuel bubbles out of the supply line.
I also dont use an external fuel pump. I have lost count of the DNF cars I've toed off track with burnt out
external pumps, The pump needs to move typically at lest 10% of its capacity continuously,
if it starts to dead head the pump motor heats up and then the wiring and relays which raises the load
and it spirals worse and worse. (You can test this just sitting with the engine idling. IR gun, and a fuel
pressure port on the rail and at the supply port on the pump.
I know if you'r going to big enough power, yea, you'r going to maybe need a pump that can't be internal.
At that point a GOOD regulator that lets the return happen without causing too much back-pressure to
the pump and still provides the pressure return relief is a must have. Its not much different than sizing a
wastegate, the regulator is a major player in the system.
Checking both rail pressure AND pump head pressure is important, if the pump goes in to internal bypass it
cavitates the fuel and heats both the fuel and the pump up.
