What is the best adjustable fuel pressure regulator that fits in the stock location for the price? Thanks.

 

I have been pleased with my Holley 512-501 FPR. FYI, many will respond that the stock unit is acceptable.

 

There is no logical reason to use an AFPR, unless your injectors are maxed out, and you don't want to buy a larger set.

 

I have a feeling they will be maxed out when I get my pressure right. Thats one reason I bought it. The other is down the road I plan on doing some more major modifications and would need it then. However, if I turn up the pressure will that hurt the injectors? What is a "safe" pressure for stock injectors?

 

The stock AC Delco injectors do NOT like high pressure. I wouldn't risk running them above 60psi. They will lock up. You can't seriously be thinking of running a heads & cam engine with the stock injectors by cranking up the fuel pressure? To get the stock 24#/HR injectors to flow at 36#/HR, you would have to crank the pressure over 90psi (flow increases with the square root of the pressure ratio). The injectors will lock up, and the flow capacity of the fuel pump (unless its a special high pressure pump) will be reduced to next to nothing. A real recipe for disaster.

Rather than spend you money on an AFPR, but a set of injectors that will allow you to meet the increased HP levels you anticipate in the future. Get some 42#/HR injectors, have the PCM programmed for them, and you will never have to buy another set, unless you go to boost. The injectors are not that expensive.

 

Lol i just meant slightly not 90 psi.

 

Unless everything in the tune is also adjusted properly, adjusting the fuel pressure "slightly" is a super ghetto/bad way of tuning an LT1 (if you could even call it tuning).

 

OK.... let's just crank up the pressure "slightly".... let's say from 43.5psi to 50psi. Your stock injectors (programmed as 24.9 #/HR) will now flow 26.7 #/HR, good for about 380 HP at the flywheel.

 

Agreed, but Holly if you must...