I have a 1990 F-150 with a GT40 302. Has anyone done a computer and engine harness swap to get a map sensor application? Id like to put a GT40 intake on it. The way it is has stock intake and engine harness and motor has never been tuned. Any ideas or suggestions?

 

What is a GT40 302? Can you elaborate further on what the motor is equipped with. A '90 F150 already has a MAP sensor in it, did you mean MAF?

 

A Gt40 302 is a high performance motor that came in mustangs. This one has cams, high compression pistons, roller rocker heads with porting. I was told that with a 1990 engine harness, the motor couldn't tune itself because it didn't have a mass air sensor. (Maybe I was confused on what the correct name of the sensor was.) So I was told with a 94 and up, the computer and harness was equipped with this mass air sensor. I'm just trying to get this figured out because its an awesome motor but hasn't ever been tuned. It never ran near its potential.

 

All Mustang with v8s built 1989 (1988 in California) and later came with mass air flow (MAF) sensors and programming in place of the older speed density programming that made use of the manifold absolute pressure (MAP) sensor. The MAF programming can better tolerate after market add-ons up to a certain point; bigger cams and heads allowing for up to about 350hp were possible. Beyond that required reprogramming the computer, installing bigger injectors and a bigger MAF sensor.

There are many sources that describe converting a SD computer/harness to a MAF system; mostly by the Mustang folks. But if you really have a 1990 harness and computer from a Mustang, you should already have a MAF system. Look at the intake air tube. If there is an aluminum body with a wiring harness in between the tube and air filter box, that's the MAF sensor.

The 302 GT40 engines came in SVT Cobra Mustangs from 1993-1995, but advertised power was only about 25hp over the non-GT40 HO engines. Other "GT40" engines were available in Explorers/Mountaineers between 1996-2001. They got GT40/GT40P heads on 302 blocks, with similar power ratings. They all had MAF sensors and matching computers.

 

So your motor has a stock Mustang intake on it or a stock truck intake?
I'd suggest you dig into a motor a bit to determine exactly what parts it has, I'd wager you were sold a hugh pile of BS and this is nothing more than a stock 5.0 with an aftermarket cam.
Can you verify that it actually has GT40 heads? You should see the designation cast into the outside corner near the head bolts, and if the intake is removed you will find the casting numbers under one of the central intake ports.