[JJKJ]

With the upgrades I'm performing to my 72 350, I'm adding a 4bbl e-perf intake and carb. The carb is a 76 Pontiac q-jet. My questions are:

What is the difference between 4bbl fuel pumps? I see that the AC equipped cars (which mine is) have an extra vent for 72-74 cars. However, besides that what is the difference between a 72-74 4bbl fuel pump and a 75-79 (these are the years PY groups together)?

I'm also trying to figure out which fuel supply line to order from the fuel pump to carb. All the q-jets with front inlet should be the same correct? PY's catalog shows one part number for a 71-74 4bbl fuel line and a different one for 75-79 4bbl. I don't know why there would be a difference. The pictures show them side-by-side and they look very similar. Any ideas?

Basically I'm trying to ensure I have the right parts to put the 76 carb on my 72 engine.

Thanks,