I think it's worth installing even if to benefit cylinder #6, especially on VP44 trucks, since the intake plenum has a pretty large hump near the intake horn cast into it that certainly has to be a bit restrictive.
You would not need a tunnel ram if you used a spool aid
I made these for 3rd gens. There is a member on here that I made
one for that never used it. I made them to feed front of head, and
rear. You would need to cut off front pipe and weld shut, the rest
should work the same. The kit I made him also has a tool to put rear
plug in. I gave him the kit for free, with everything you need to install
you would need to buy nothing. His name is George Malusia, not sure
how to spell last name. Tell him I told you to contact him about it.
He paid nothing not even shipping.