Hey guys I've been working on a sweet wagon all summer.. Got it with a blown engine so swapped an engine from my old 300sdl that the trans quit on me.. I learned the radiator was no good after cooking the trans in 12 miles because it was mixing water with trans fluid.. Swapped the trans from another donor sdl and now I'm not sure if I have the vac lines hooked up correctly but when I hook up the vac line it shifts very smooth but sometimes hesitates shifting 2-3rd and 3-4th and seems to slip sometimes in 4th.. When I unhook the vac line it doesn't slip just shifts hard. I read about popping the plastic cap off and adjusting the vac fitting on the trans but figured I'd ask before adjusting stuff. I'm hoping it's just adjusted so it's shifting too soft and not fully engaging?

Thanks guys and I have one of those green pieces in between the line going to the trans.