TaddMason2005

So I'm wanting to twin turbo a 5.4 2 valve and put it into my 94 flareside and make it a drag truck. So my question is how much boost can a stock 5.4 2 valve bottom end hold? Also would this be a hard swap over the 5.0 that's in it.

Flareside1992

Im not sure about any of the questions you posed but if you build it keep us posted! Sounds like an awesome build

TaddMason2005

I sure will. I'm starting build in next couple weeks. Have to rebuild front suspension and get rid of ALOT OF WEIGHT

sdmartin65

Not sure on question number one, but I'm sure it depends on condition and miles on the 5.4.
Question number two, how hard to swap in a 5.4 in place of a 5.0 in a 90's obd1 truck. Keep dreaming big, that's how difficult I think it is! 😀

TaddMason2005

I'll have the ECU and all the wiring harness. I'd I seen a 4.6dohc SC out of a 04 cobra put in a crown vic 6 speed and IRS quite easily then I'm hoping shouldn't be a problem for me

sdmartin65

The Crown Vic would have correct electrical system to run a 4.6. The 5.0 and 5.4 are completely different generations and in my thinking would require switching many components to match the 5.4. Trans control and engine management along with speedo cluster. Seems daunting to me but you probably have more skills. In any case good luck to you.

Manuellabour247

Mounts, wiring harness, exhaust, cooling system, e-fan. That is where I would plan on the most differences in the swap. My advice would be to have a complete donor that the power plant is coming out of and don't scrap it until your truck is running correctly. There's going to be all sorts of issues with this swap, but hopefully not any major ones. You might also have to swap the braking system over to the newer style with all of the electronics. This is why I say have a donor.

Anything worth doing is going to be hard. Sounds like an interesting build.

TaddMason2005

Yeah kind of planned on getting a donor truck for the build. As far as gauges I'm planning on my own custom cluster with autometer gauges. The rear axle is another thing I'll be robbing for it already has rear disc brakes "you can go fast but got to stop good as well" I know I have some great people saying they'll help back me on this build if I decide to do it so wish me luck and keep everyone posted as this dream becomes a reality

Manuellabour247

Completely missed the turbo. With that you'll probably have a stand alone ECU for the engine anyways. That would work better for you in the long run if you're going to do custom gauges. Are you going to build the 5.4 or just stick it in the truck and run low psi for the turbo? While you have the engine out, that would be a good time to redo the internals and have the engine checked for weak spots.

Upgrades I would do while the engine is out getting ready for transplant-

1. Upgrade studs for the heads
2. All new gaskets
3. Beef up the internals
4. Valve job to run the boost and hold it
5. Degrease everything and paint it for looks (nobody likes a ****ty looking engine bay Lol)
6. Go through the transmission and beef it up to hold the power long term.


All of this is if you want a long lasting toy. I'm sure that it would last a while, but I'm also sure you'd get bored with the power you start out with. Haha. Better to overbuild than to underbuild and have a block with a window.

TaddMason2005

Running E89 run bout 15 pounds of boost on twin 72mm turbos "I have" and are new already talked to a good friend of mine who souly rebuilds ford trannys he's going to beef it up for me. Complete new gaskets were a given so I don't have any suprise leaks. Head studs and valve train were already a given looking for a cam that will work with boost. Any more questions feel free to ask. If there is anything I'm missing on my prebuild checklist let me know. Not planning on going to crazy right now eventually like to do a 4 link but that will be further down the road