I just cut the fittings off of a fuel filter and silicon bronzed (TIG) a -8AN(JIC) fitting to them. If anyone needs a -6 or -8AN fitting for the stock feed line on the frame, PM me. If you are converting to AN hose/tubing, then use the stock feed line as the return, and use either a -6AN or -8AN new feed. The stock feed line necks down to .257" at each Saginaw fitting. The stock feed line will only flow as much as a 1/4" tube (600+HP). A -6AN is 11/32" ID, which is big enough to feed over 750hp at 65psi. A stock fuel system will feed enough fuel for a 9.90 run. (it HAS been done)
If you use Push-lock hose, be sure it is rated for gasoline. Parker Push-lock hose is NOT rated for gasoline. It will work, but must be periodically inspected. Some folks are complaining about fuel vapor in thier garages when using braided steel AN hose, too. The only way to completely eliminate fuel vapors from escaping AN hose it to use TFE (teflon) external braid hose.