69SSTPI

I would like to modify the fuel pressure regulator return line to face the rear. Searching previous posts on here make it look easy with fittings from street and performance, but I can't find any parts available from them. Then I see post about just tapping it to 1/8 npt, but they say the fpr could easily crack in the process. I could also just cut the return line keep the o ring fitting end and compression fitting off of that to 5/16" hard line. What is the current best way to change to a different style return line from the fuel pressure regulator. Ideally, like this picture I found on here. Thanks, formal introduction to follow in a different post.

Komet

I screwed around with this a lot, and in the end I couldn't get my NPT connections to seal at 43.5psi. They did at first but blew out the thread sealant after ~30 minutes of runtime. If you have the ability to cut ORB sealing surfaces, that might work. 1/8 NPT won't crack the stock FPR base, in fact the hole is too big for 1/8 NPT so the threads don't cut deep. Maybe if I used a starter tap and then switched to a bottoming tap, and got the perfect alignment with the perfect cut and the perfect thread sealant with the perfect torque spec, it would have sealed. It was very close to working, but very close doesn't cut it here. I ended up taking my rails to a welding shop and had them seal up my fittings for me:



They only charged me for an hour of work so the cost wasn't extreme. Feed comes in straight off the driver's side rail, original feed on passenger side rail had steel insert removed and it was welded closed with an aluminum plug. I was having trouble with my used AFPR regulating below 46psi so I had the rear crossover welded shut as well and I used a full flow 90 degree AN bend fitting on the rear of the passenger rail to return to an external AFPR. Most aluminum NPT fittings come anodized, Easy-Off HD Oven Cleaner (yellow can) fixes that right up.

If you want to keep the stock regulator, a cut and flare of the original hardline might work. Compression fittings are unacceptable for gasoline applications.

69SSTPI

Thanks for the advice. I also removed the steel insert and tapped it with 1/2 npt and plug. Three turns of the plug until tight. I dont know if i like it yet. I should have just left the steel insert in and plugged it with the 3/8 16 bolt that i used to extract it. I dont think there will be enough room to flare the return line after cutting it at the bend where it goes into the fpr. I plan to use the cold start injector threads for fuel inlet. Im still unsure on what way i will end up doing it.

Drgnbld

iTrader: (3)

First TPI states their fuel rails can be used for the GM TPI with modification. When you order them you just have to state that they will be used on the GM set up. I just ordered a set so Ill see if they come already modified.