1998 Tacoma 5.3L Vortec (LS) Engine Swap Thread

Time for headers/exhaust manifolds. I initially test fit a pair of Patriot cast iron manifolds, as they hug the block really well. There is not much room on the left side of the engine.



The headers fit on each side...


But unfortunately the left side exhaust output was pointing right of the base of the steering rag joint/connection to the steering rack. It needs to come out a little higher to clear the stock steering shaft and transmission bell housing.



I also looked into flipping the left header only towards the front, cross over the front of the engine and then to the back and merge with the right header somehow.


It might have worked but there wasn't much room below the engine mount and around the starter. You might be able to snake an exhaust through there?

 

I sold the Patriot headers and purchased a pair of junkyard truck manifolds pulled from a 2009 Silverado for only $63.



In the pictures above, you can see I also added the starter, transmission dip stick, and oil filter.

 

Left side exhaust manifold:


Right side exhaust manifold, they are slightly different.


The first thing I did was chop the huge flanges off the output as there was no way they would fit. Right side first, chop off a section, install it in the truck, and take a look where the output dumps.





The main obstacle on the right side were the brake lines.

 

I broke down the exhaust into sections and used ball flange couplers to connect each section together.

For connecting the exhaust manifolds to the rest of the system, I used these 2.5" mild steel couplers (Hedman Hedders part #21151): https://www.summitracing.com/parts/hed-21151

The right header was cut a little shorter to dump higher and further away from the brake lines.



The one end of the coupler was hammered into an oval to better match the manifold shape.


Tack weld the pieces together (don't forget the flange!) and then test fit on the truck to make sure its clearing everything (no pics).


And fully welded.

 

The opposite coupler was welded to a 45 degree mandrel bent tube: https://www.summitracing.com/parts/sum-670175

 

Right side exhaust manifold installed.




It was coming out kinda low next to the transmission, but I decided to wait to fab up the back end exhaust before making any modifications.

 

Left side was more challenging.

I first cut the stock flange off.


And test fit to see what we are working with.



The goal is to keep the stock steering shaft to the steering rack, so over and around I need to go.

 

I cut a little more off after the first test fit. Here is how I necked down the shortened left side manifold to dump high and to the side of the steering shaft, using some pieces of 2.5" steel pipe:

 

A coupler was then welded to the necked down portion and O2 sensor bungs welded on, the one on the right is a screw up, I just capped it.





I also used one of these 2.5" 180 degree mandrel bent tubes (https://www.summitracing.com/parts/sum-623032) and cut up sections to get the exhaust to the back:

It's hard to see in the following pictures but I just barely clear the stock steering shaft, there is like 1/2" of clearance!

 

Excellent work.

 

This picture shows the O2 bung location on the right side manifolds.


I was able to use the stock heat shields on the manifolds as well, some trimming towards the output was required.

 

Thanks!

 

For the rest of the exhaust, I used a Y-pipe, catalytic converters, and muffler pulled from a 2003 4WD Yukon, found in the local classifieds for $50. I need to keep emissions.



Here is the start of the right side exhaust, flow is from bottom to top in the image. A 3" coupler (https://www.summitracing.com/parts/hed-21152) was used at the top to connect to the muffler end.


And the muffler end, I was able to keep the stock Yukon output pipe from the muffler.



A hanger bracket was fabricated to interface to the stock Tacoma muffler hangers using Chevy rubber isolators.



Some early mock ups of muffler placement.

 

The engine hoist worked nicely as a 1 man bed lift.



One of the welded on nuts in the bed frame did break and a sawzall was required to cut the bolt between the bed and frame mount. Taking off the bed made working on the back end exhaust easier. I also decided to get rid of surface rust and paint the frame. And lastly the fuel pump will need to be upgraded, no need to drop the fuel tank for access. I stored the bed on jack stands behind the truck during this process.

 

Back end exhaust finished up.

 

Here is the left side cat exhaust section, with a new post cat O2 sensor installed. The stock O2 bung was pointing straight up when installed on the truck and would not work (its capped in this image). This section bolts up to the right side exhaust via a coupler below the transmission tail shaft. For these 2.5" ball flange couplers (left side in image below), I used cheaper ones made by Walker (part #41723 and #41726):

$15 Walker 41723 Exhaust Pipe 2.5" Inlet (OD) 2.5" Outlet (ID)

https://www.amazon.com/gp/product/B0017LXW88/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

$16 Walker 41726 Exhaust Pipe 3" Inlet (ID) 2.5" Outlet (ID)

https://www.amazon.com/gp/product/B0015KZL26/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

The same ones could probably be used at the exhaust manifolds to save a few bucks.

 

I made use of the stock Tacoma exhaust hanger on the transmission crossmember to support the exhaust crossover below the transmission tail housing.



Above the left side cat, I used multiple pieces of bent sheet metal as a heat shield. I used the stock threaded studs in this area to hold them in place.

 

Here is how I connected the left and right side exhausts together below the transmission tail housing:





Left side cat under shields, the parking brake line is not shielded here.



The stock Tacoma exhaust shields were kept on the right side, some cutting and massaging was required to clear the exhaust.

 

Following!

 

For the fuel pump, I went with an AEM part #50-1000: https://www.aemelectronics.com/prod...0lph-high-flow-in-tank-fuel-pump-offset-inlet

At 58 PSI, the pump flows 305 lph, which should be good for a stock 5.3L swap. I don't believe this would work for high horsepower and boosted applications.

There are three lines coming from the gas tank that go to the front of the truck. The top one in the image below is the pressurized line that goes to the fuel regulator by the engine. The next one below it is the fuel return line, also coming from the fuel regulator. And the bottom line is a vent for the evaporative emissions system.



Taking off the bed gives easy access to the fuel sender unit on top of the gas tank.



Clean the top of the tank so no debris falls in the tank. Take off the gas cap to de-pressurize the tank, disconnect the fuel lines at the top including the connector for power/fuel level signal, and then 8 or so screws need to be removed to separate the sender unit from the tank. Here is the stock sender unit.



Stock Tacoma fuel pump separated


Here is the stock Toyota fuel pump connector and power wires. The AEM connector in the background will get attached to this connector that goes to the top of the sending unit.


I then attached the larger wires that came with the AEM pump. Pull back the white clip on the connector, lift up the plastic tab holding the pin, and push the pin out.


Solder the larger AEM wires to the pins.


Re-insert the pins into the connector.