Here's my future setup. I just ordered a walbro fuel pump, but the guy is asking me now if I want a high pressure or low pressure fuel pump. A low pressure being good up to 60psi, and a high pressure is only recommended for applications over 60 pis. I know it all depends on tuning, but 60psi seems a lot. Here's the setup:

Vortec heads
350
TPI
LT1 injectors
Full exhaust
Lt4 Cam - Not hot cam.
Forged internals.
Looking for 325flywheel HP and 25mpg, so with custom tuning and all will the low pressure be enough?

Thanks for any and all help.

James

 

I'm going to ASSume here that the high pressure pump is a 340 and the low pressure is a 307. Just go with a 340, it works fine for me.

 

It's a walbro 255lph, just one is low pressure (below 60 psi) and one is a high pressure (above 60 psi) Which one ois the best to go with? It seems to me that I could get the high pressure and just let the AFPR control it down to 50psi, wouldn't this give me better pump life as well by not taxing it so much?

James

 

The 340 pump draws less amperage in our operating range of 40-50psi...that's why I snagged one. Plus, when I eventually put an LS1 under the hood I'll already have a fuel pump that can deliver the 58psi it wants.

 

I had the same question and sent them an e-mail, this is the response :

The GSS340 has the same volume rating as the GSS307. The only difference is that the GSS340 has a more efficient motor in it so it will draw less power for the same given output as the GSS307. Most people opt to buy the GSS340 as it gives them room to grow if higher pressures are required. Both pumps are street pumps with the same hour-life rating

 

I decided to go with the 255lph high pressure pump and just let my AFPR deal with it. Probably be a pain tuning it, but we will see. Since the plan is an SC in the future, I think it is better to go this route now, instead of ripping out my tank again in the future.