I have an 83 f150 that i have replaced engine with 96model full roller motor 5.0 and have replaced the rear end with an 8.8 ls with 3.55 gears and also the dana 44 in front with 3.54 gears. truck is currently running a granny 4 speed with a np308f transfer case. my question is what 5 speed do i need to replace the 4 speed with 3000 rpm at 70 mph is just too much i need a 5th gear thanks

 

Find a zf tranny from the 87-96 trucks. Should be a direct replacement for your np435 4spd but if you can it wouldnt hurt to get crossmember and driveshaft too. This does require a hydralic clutch conversion i think. The mazda 5spd fits but isnt as strong. Run a google search on a 5spd zf swap