Have 1986 f150 with speed density and aod tranny.Fixing to drop 1998 explorer 5.0 with gt40 heads in was wondering if the gt ecu would give more go than the f150 one.Any suggestions for add ons with speed density?

 

Chances are the speed density PCM will not be able to control the newer engine properly. If you can use the mass air from the explorer, by all means do so. You will need the mass air meter and will probably have a lot of splicing to do. I converted a 92 Bronco to mass air for a built 351 several years back and used the 93 mustang PCM. That engine would never have run right with speed density.