91 tune...
 

1997 f150 5.4L. Installed the gryphon and used the 87 custom tune, and very pleased with the performance of it. I tried the 91 custom tune and it has less power than the 87 tune. Someone told me that that seems to be common that in these trucks the 87 tunes give more power than the 91. Is this true or could there be a problem with the tune?