Finally getting to publishing a bit of info on the latest Silverado upgrades.
Early October it was decided to do a maintenance item, water pump. In doing so, it was only fitting to upgrade parts of the 5.3l. Right? Since you’re in there, might as well add some bolt-ons.
Being the 5.3l has 180k miles on the original bottom end, I ordered:
- BBK 80mm Power-Plus Throttle Body
- Granatelli Motor Sports Mass Air Scensor
- MSD Blaster OEM Replacement Coils
- PCM of NC LS Dual Electric Fans
Everything but the fan kit was ordered through SummitRacing.com.
The install went smooth and being on a time crunch, I failed to take pictures of all the steps.
Step 1: We removed the factory radiator shroud along with the clutch fan gaining access to the water pump. The only notable here was getting a pipe wrench on the clutch fastener since we didn’t have wrench. Removal of the clutch fan fastener took little effort, surprisingly.
*Pro Tip: The thermostat on a 2003 factory 5.3l includes the water neck, they’re one unit. A 160 degree thermostat was recommended yet opted for a 180 due to Washington winters.
Step 2: Removed the K&N Cold Air Kit from the factory throttle body and moved onto removing the factory throttle body.
Step 3: Installed the replacement water pump, thermostat, new air conditioning and rotating assembly belt.
Step 4: Installed the mass air sensor.
Step 5: With the BBK throttle body, the factory linkage had to be pulled out of the factory throttle body to use in the new unit. However, the pulling tools supplied by BBK were junk. So, doing the next best thing, the factory throttle was drilled as to punch out the linkage because the factory throttle body was being tossed. The linkage then assembled and fit into the BBK easily and works good to this day. Then the factory gasket was reused since formed and still fit nicely onto the factory intake. After installing that portion was done.
Step 6: My buddy installed the PCM wiring harness for a 3 relay and plugged the pins into the ECU slots. While he did that, I installed the LS series dual fans onto the radiator and moved some factory wiring to further improve the installs cleanliness.
Step 7: Connected the remaining water hoses, filed with water (allowing time for the radiator to fill), connected the K&N air tubes to the mass air sensor and throttle body.
Step: 8: The ECU was sent to PMC for tuning. The tune included the fan switch activation and settings (since the ECU had a factory flash) for a Monster SS transmission,BBK headers and Flowmaster mufflers, BBK throttle body, Granatelli mass air scensor, 180 degree thermostat, K&N cold air, and MSD coils. Also, the ECU was set for 92 octane since that is what we have in the PNW.
The power increase was good. The motor runs smooth and has more throttle response, with a slightly audible throttle body whistle. With the Monster transmission, from 1st to 2nd gear shifts, the truck either barks hard (sounding hella cool) or breaks traction and posi’s out a bit. I’m impressed.
Based on ‘seat of the pants’ feel, the Silverado is a respectable 315hp yet wouldn’t mind seeing a dyno sheet – maybe this year.
The work took about 7 hours from start to finish with delays caused by beer and bullshitting. It was really straight forward and good for any amateur enthusiast since the only fluid drain came from the water pump install.
First Start of the Silverado Upgrades