I have a 91 F150 with a 5.0 I am thinking of replacing it. Can I use a motor from a mustang GT or Lx.? What changes would i have to make. What about a ford crate motor like a gt40 would that still pass emissions in Massachusetts?

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1991 F150 71,0000 5.0 auto,black longbed 4x4

 

refresh

 

This is the fix all for passing emissions. Just run 2 bottles of heat in a quarter tank of gas when you take your test.(the stuff you use in winter so you don't get water in your gas tank) The heat is just alcohal and runs hotter which will make your emisions less. So do what you want to your engine, you can still pass emissions. I pulled off all the emissions on my mustang and still pass the 30 second quick pass like this. It really does work. The mustang motor will fit, just the mounts will need to be changed but you will have the old ones. Crate motors are cheap now so that is a good option.

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1997 f150 4x4
extended cab, xlt
4.6, 5 speed 3.55 gears

 

Just don't be surprised if your truck with the Mustang motor performs like cr@p. Torque and hp curves are different for a small lightweight car from those for a heavy truck.

 

What about the GT40 long Block will it be able to pass emissions and will it perform?

 

The 5.0s are a different story than the 4.6/5.4 modular motors.

I would stick a mustang engine in a bronco or truck if it had a 302 stock. The torque the stang makes is about 500-1000hp higher than the truck motor, but the HP would make up for that. Just depends on how much you tow. You can always get a different cam in there (not the truck one). Also add things like a intake spacer to increase low end. The only problems I see is the intake. Again the TB and all is facing the passenger side. On the stock 5.0 intake, no big deal, just flip it around. But if you go aftermarket with a cobra or GT40 intake, you cannot do that due to the staggered ports. The truck lowers flow more air than the stock GT, but the upper is kind of weak for flow stock. Basically with the roller valvetrain, intake and cam, that is where the power difference come in from the Fseries to the stang 5.0.

Emmissions -- ALWAYS check with your local state laws for what is legal. They all vary.

 

as far as performace andpassing testing consider this. you r current 302 makes around 185 h.p and 270 ft. lbs of torque. a gt motor makes 225 h.p. and 300 ft lbs of torque. they have the same compression, bore stroke. the only real difference is the gt motor has a more aggressive roller cam, and factory headers(kind of). the only consern i would have is if your truck is speed density or mass air flow. if it is a mass are flow i would go for it, if it is speed density i would consider converting it to mass air flow. all of your current assesories bolt up. sound like a great swap to me and the gt-40 crate moter with the E303 CAM WOULD BE EVEN BETTER.