LT4 HPFP on LT1 - Plumbing
 

So a year ago I upgraded to a LT4 HPFP and the 12677004 "45" pipe that goes between the pump and the distribution block that feeds the rails, but was there a LT4 specific tube that goes from the HPFP to the quick connector on the driver's valve cover? I guess it would be the HPFP inlet?

You might be talking about this line right?

was there a difference in the piping when you did the swap?

https://paceperformance.com/i-201648...pump-pipe.html

do we need that? If so i will order ASAP as my build is practically done

Are you sure you didnt misunderstand and didnt hear the tube from the pump to the rails?

Lt4 I thought was straighter and maybe a tad larger to help with starvation.

Dysan - yes, that is the plumbing I am referring to. Mine is like yours pictured, it has the short piece of flexible line (my car is a LT1). What I see is Jannetty has a LT4 inlet pipe on their site, it doesn't have the flex line (I would assume this is where the restriction might be?)

https://cdn.shopify.com/s/files/1/24...g?v=1537545882

FYI - this is the updated mid pipe, the newer, high flow one has the double 45 degree bends, where as the original had one 45 deg, and one 90

https://paceperformance.com/images/M120705593.png

You will want the Lt4 low pressure fuel line, the flexible one in the LT1 version has a restriction orifice in it, the LT4 doesnt have that orifice.

Does anyone have a GM part number?

If your going to this much trouble Lingenfelter makes a hi flow line with a better ck valve. I picked up 10 psi on low side not changing a thing but the line. By now it should be for sale I had to go off some engineers directions. When you go to UWE or kaytech belt driven setup all the restrictions are non existent there's a bottle neck there that no one really speaks about.

My biggest reason for asking is that I am going to place a large order to finish my engine build for my GM parts, want to add this to it.

I'm still running my stock LT1 tube and my low/high side pressures are holding up fine. Be that as it may, I would have swapped in the LT4 part if I had known at the time that there was a difference.

What does it mean?
What is a "Belt Driven Setup" in terms of fueling?
Who are UWE?