YOUR MY HERO I WAS WAITING FOR YOU TO CHIME IN I DIDNT THINK THAT IT REALLY WOULD MAKE THAT MUCH DIFFRENCE IF ANY AT ALLWhy is what I have to ask. I ran a fuel pressure gauge on stock injectors with a stock fuel system and did not notice any fuel pressure problems. 2psi drop is all I would get at WOT. I still have those same stock banjo bolts in my truck and I have B code injectors, I see a 0psi drop in fuel pressure at WOT.
Again I will have to ask, why? I just don't see the need. It can't hurt anything as long is you don't mess anything up doing it. My one concern is drilling the holes out and breaking it on reinstalling the banjo bolt. Plus I fairly confident that if you do the math, the 4 stock 1/8" holes outflow the 1/4" outlet in the banjo bolt.
ok i wil my gauge is the defuser kit and its hooked up at the fuel filter bowl,i got it when i was paying with the fuel pressure regulator shims,works goodLet us know how it works out and if you get any more pressure drilling out those plugs.
Where is your gauge hooked up at?
where are those check valve fittings and what do they do?Like I said in my earlier post, this mod is not necessary. You don't need to use those fuel ports to make 500hp. The 1/8" NPT supply ports on the top of the heads are just fine. The bigger thing is getting rid of the stock fittings and the POS check valves.