The 1990 Ford F-150 can have either the :
4.9 liter ( 300 cubic inch ) inline 6 cylinder
5.0 liter ( 302 cubic inch ) V8
5.8 liter ( 351 cubic inch ) V8
281 cubic inches for the Ford 4.6 liter V8 engine
for what size of engine ?
It would be a 289
C6 or an aod
Need to know the year and size of engine
That would depend on which engine size you have
In order to determine the size brake line for a 1990 Ford T F 150, you will need to know the size of your drum wheel cylinders. You also will need to know what kind of disc calipers you have.
A little more information please ( model year of Ford F-150 , engine size )
In a 1990 Ford Aerostar : You either have the 3.0 liter V6 engine or the 4.0 liter V6 engine from the factory ( each size of engine has 6 engine cylinders )
4.9L Inline-6, 5.0 v8, 5.8L V8
Click the link and choose your engine size.
7.3 liter diesel