I am using parts store 3/8 fuel line with Dorman fitting to connect two lenghts together. I then purchased a Dorman nylon repair kit ( P/N: 800-058) that has the OE GM connector on one end. It comes with a brass barb to connect to teh existing nylon line. I found another Dorman fitting that is designed with compression fittings, one for 3/8 hard line and the other for the nylon. The fix kit is about 18" long...
I has also purchased some 3/8 compression to -6AN fittings off eBay... but making AN lines is more money.... so I'll try the nlyon lines first... I did however but some heavy heat shrink tubing to increase any abrasion or puncture resistance of the nylon ....