Ive had to replace both the inlet and outlet lines on mine in the last year or two. The previous came from one of the resto vendors and eventually started seeping.
Currently running the push-lock type thing on the inlet. My local Napa helped me with that. I have a 12 inch grease gun hose on the outlet. The grease gun hose scares me a bit. What little info I’ve been able to find, suggests the heat rating of grease gun hose is kinda borderline.
The next time I replumb, it will be with “braided steel oil return” line. You can buy it with a black PVC coating that wouldn’t look totally wrong. Sold in several different diameters, lengths, and fitting arrangements. Not too expensive. Look for a seller called “EZ Dealers” on the big auction site for examples. But several sellers have similar. “Inline Tube” sells many options of the same.
