ok i think i've done a lot for for my 3 valve.
but on a 2 valve the y pipe is and has been it's biggest problem. get rid of it. headers as i said 12 stinking hp all up stairs it's lost low end.the air intake kit not the hp claimed by afe thats for sure. but it sounds great and turns heads. most of my gains are from about 100 pulls on the dyno , a awfull lot of time on the computer playing with the tuning, some times it went up. then down with another. and in the trans. the trans looses a lot in the torqe reduction programing and slip.
it took a lot of tuning time , pulling the trans and replaceing clutches and disc's haveing the converter redone .furnace brazing, needle bearings. different clutch and disc material, if you want big gains it costs big time money.
yes gale banks puts out most likely the best bolt on gains you can get. a good tuner can pull out maybe 15 or 20 more in programing. but gale is a diesel man. kenny bell. yes he's a super charger man. most likly one of the best right now. again it cost big $$$$.
it's just how much do you want to or can you spend, we do not have light trucks here, they are heavy weights.