Another 454 Vortec Build Thread - Documenting, Q&A, Help

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Bachert24

OBS Enthusiast
Joined
Apr 17, 2024
Messages
63
Reaction score
24
Location
Cedar Springs, MI
With some encouragement I decided to start my own build thread. This may be slow going but I will try to document everything I do, I will need all your help as there isnt much in the way of parts out there for this thing. As far as I know this thing is stock. 207K miles and attached pics is what I am working with as it sits. All I know is the guy my son bought it from said it ran great but needed a tune-up. As he was driving home it would not go above 35mph. The exhaust is missing and the rear passenger drum is missing and brake line is detached. Has been sitting 9 months and I finally got it running again so I can drive it 35 miles home, hopefully, tomorrow. There is a ton of random switches I have to see what they are for, my guess is plow and remote wire switch for amplifier as the reminder of the wiring is still there. I have been a backyard mechanic for 25 years, I do it all, electrical, monarchical, I fix my own appliances, I do cars, houses, you name it lol.

What I have done so far is just spart plugs and cleaned the battery terminals.

What I know it needs, rear brakes, finish tune-up, new fluids, front CV axle boots, rear diff cover/gasket.

On my agenda long term, depending on how it runs on the way home. Fuel pump, any reason this one wont work? https://www.highflowfuel.com/genuine-walbro-ti-350lph-fuel-pump-ti-gss352g3/
Fuel injectors if needed, suspension rebuild, frame rust converter coating, new wheels and tires, I have purchased 2 cats, 2 mufflers, and 2 tips, will have shop bend and install the remaining piping. 0411 swap (please link me to the best video you have found)

Need from you: will that attached fuel pump fit the housing and wire up fairly easily? Recommendation on fuel injectors. Other must do parts

Longer time hopes: Cam, heads and valvetrain upgrade, projector headlights, windshield, radio, rear disc conversion (cost effectice DIY kit options?)

My wife has given me the ok to do whatever I want as long as it isnt ****, she likes trucks and a mean low rumble is what will make her happy lol. This is a 21foot camper hauler and badass toy so I will be adding power. Truck already has 4L80E tranny and 4:10 gears so a solid start there!
 

Attachments

  • 1.jpg
    1.jpg
    443.2 KB · Views: 27
  • 2.jpg
    2.jpg
    493.4 KB · Views: 28
  • 3.jpg
    3.jpg
    483.3 KB · Views: 29
  • 4.jpg
    4.jpg
    374.4 KB · Views: 28
  • 5.jpg
    5.jpg
    445.6 KB · Views: 27

Scottm

I'm Awesome
Joined
Aug 24, 2021
Messages
313
Reaction score
234
Location
AZ
This guy Tolman has a lot of great vids on upgrading the Gmt400 trucks. This 0411 swap vid convinced me to make the jump. But I went way further and basically reran every wire from ecm to sensor. I was having strange problems with the 4wd, and it turned out to be wires burned up from exhaust heat, which I never would have found without a complete teardown of the harness. Here's my truck in june last year..

xc_hide_links_from_guests_guests_error_hide_media
 

Attachments

  • IMG_1932.JPG
    IMG_1932.JPG
    312.4 KB · Views: 17

Carlaisle

I'm Awesome
Joined
Oct 14, 2019
Messages
254
Reaction score
300
Location
Required
Going to have a hard time convincing me it sunk that far into the dirt in 9 months.

Looks like your rear shocks are toast.

It's rare for the differential cover gasket to leak unless someone opened it up. This may be exactly what happened since one of your rear drums went AWOL.

The lower half of your fan shroud is missing. A front skid plate, even the plastic one, would be wise to install.

No properly engineered rear disc conversion is available. If you want more stopping power, go with the same make/model/year calipers and rotors for the 3500 up front - they'll swap right on. I think the big rear drums and hardware will swap on, too.

If the fuel pump is working there's no reason to replace it. Check the key on engine off pressure and if it is within spec, clean up the ground and just run it.

If you need injectors, take outs - or new - that fit a 1996 Ford 4.6L are plug and play - no tuning required. Many others will physically fit, 99% of those will require tuning to run correctly. If those are still the original injectors, they are junk even if by some miracle they are functioning more or less as intended. They would be a great proactive replacement. Be careful with the fuel injector rail. It is not available new anywhere if you damage it.

Given the body rust and rust belt heritage, the rear brake line where it goes up the frame rail along the fuel tank is suspect. That's where they all fail. if yours hasn't yet, it's due. Another great proactive replacement, especially if you are planning to tow a camper. Junk that quick disconnect heater hose fitting where it comes out of the intake, too. If it hasn't already disintegrated, it will soon.

The engine tune and exhaust are the biggest bang for the buck power adders. You can grab well over 100 lbs of torque between those two.

Figuring out why it won't go above 35 mph would be my second priority. The non-functioning rear brakes would be the first.
 

Bachert24

OBS Enthusiast
Joined
Apr 17, 2024
Messages
63
Reaction score
24
Location
Cedar Springs, MI
Ok update. Drive 10 miles today. Started out driving ok started to get slower and slower and after mile 10 would barely move. Any chance this is fueling? Seems to idle fine. Here’s some codes I pulled gonna get it towed home. Guide me almighty gmt400 gods need to know where to start to get running good.
 

Attachments

  • IMG_0341.png
    IMG_0341.png
    413.2 KB · Views: 11
  • IMG_0342.png
    IMG_0342.png
    472.6 KB · Views: 11
  • IMG_0343.png
    IMG_0343.png
    419.3 KB · Views: 10
  • IMG_0344.png
    IMG_0344.png
    323.4 KB · Views: 12

Bachert24

OBS Enthusiast
Joined
Apr 17, 2024
Messages
63
Reaction score
24
Location
Cedar Springs, MI
This guy Tolman has a lot of great vids on upgrading the Gmt400 trucks. This 0411 swap vid convinced me to make the jump. But I went way further and basically reran every wire from ecm to sensor. I was having strange problems with the 4wd, and it turned out to be wires burned up from exhaust heat, which I never would have found without a complete teardown of the harness. Here's my truck in june last year..

xc_hide_links_from_guests_guests_error_hide_media
Thank you!
 

Bachert24

OBS Enthusiast
Joined
Apr 17, 2024
Messages
63
Reaction score
24
Location
Cedar Springs, MI
Going to have a hard time convincing me it sunk that far into the dirt in 9 months.

Looks like your rear shocks are toast.

It's rare for the differential cover gasket to leak unless someone opened it up. This may be exactly what happened since one of your rear drums went AWOL.

The lower half of your fan shroud is missing. A front skid plate, even the plastic one, would be wise to install.

No properly engineered rear disc conversion is available. If you want more stopping power, go with the same make/model/year calipers and rotors for the 3500 up front - they'll swap right on. I think the big rear drums and hardware will swap on, too.

If the fuel pump is working there's no reason to replace it. Check the key on engine off pressure and if it is within spec, clean up the ground and just run it.

If you need injectors, take outs - or new - that fit a 1996 Ford 4.6L are plug and play - no tuning required. Many others will physically fit, 99% of those will require tuning to run correctly. If those are still the original injectors, they are junk even if by some miracle they are functioning more or less as intended. They would be a great proactive replacement. Be careful with the fuel injector rail. It is not available new anywhere if you damage it.

Given the body rust and rust belt heritage, the rear brake line where it goes up the frame rail along the fuel tank is suspect. That's where they all fail. if yours hasn't yet, it's due. Another great proactive replacement, especially if you are planning to tow a camper. Junk that quick disconnect heater hose fitting where it comes out of the intake, too. If it hasn't already disintegrated, it will soon.

The engine tune and exhaust are the biggest bang for the buck power adders. You can grab well over 100 lbs of torque between those two.

Figuring out why it won't go above 35 mph would be my second priority. The non-functioning rear brakes would be the first.
This is amazing info Hank you for taking the time to write this up!
 

Caman96

OEM Baby!
Supporting Member
Joined
Jul 17, 2020
Messages
7,439
Reaction score
14,594
Location
The Hub
The Walbro site confirms that fuel pump for a 1996 7.4 Vortec, but not a 1998. 98 pump/hanger were different than 96’s FWIW. I have a Walbro in my 96 5.7 Vortec, great pump!
 
Top