I’m converting my current 87 S10 Blazer from a carbed 350 to an LT1 courtesy of Brian. Anyways, I’m planning on running a Walbro 255 in tank pump. Here is a link
that is supposedly setup for my style truck, but will work with LT1 motors.
Anyways, I’m not exactly sure what fuel pressure this lt1 will need. I thought it was somewhere around 40-45psi. Anyone know for sure?
Also, do I need to run a fuel pressure regulator to get the correct pressure for the engine?
Any info is much appreciated.
use fuel injection clamps. i do not like those style clamps they give you for high pressure lines
usually on efi cars, 3 bar is base fuel pressure. that would be 45psi.
according to my books–
FUEL PRESSURE:
Ignition ON Engine OFF 40.5 to 47.0 psi
With Regulator Vacuum Applied [1] 3.0 - 10.0 psi Less than Ignition ON Engine OFF
REMARKS:
[1] May be checked with either of the following methods.
With Pressure Regulator Vacuum Line Attached at normal idle speed.
Ignition ON Engine OFF with 10 Inches Of Vacuum Applied To The Pressure Regulator.
last, since you are swapping a carb out to efi, --just use the stock gm regulator for this engine. alot cheaper for one of them than it is an aftermarket one.
Yeah, I was planning on that. I was looking at those clamps and they didn’t look real sturdy. I’m also thinking about using a piece of copper tubing or stainless tubing instead of that rubber line.
sorry to whore but when does the project start ? 
45 would be a good pressure to run. i think stock might be 43psi. but anywhere from 42-48 would be fine for a LT1
an adjustable fuel pressure regulator is necessary for tuning fuel pressure. but using a stock one would be best…and hopefully its in working condition as they can go bad. stay away from accel LT1 FPR’s…i have heard bad things about them…breaking and/or not holding right pressure after 1-2 years of use. Aeromotive i believe makes a nice unit but its around if not over 100 bucks
Soon! Hopefully first or second week of February. I’ll keep you abreast, you can come check it out, take ya for a ride.
Awesome, thank you so much for that info. Does the LT1 come with a stock regulator somewhere already on it?
Yeah, I’ve heard bad things about ACCEL in the past, both with their electronics and their fuel pressure units. If I ran anything, it would be Aeromotive, but like I asked sailor above, does the LT1 come with a stock regulator? I don’t plan on running anything outside of the stock engine for the first year or two, before an eventual bore out/stroke to 383 and a cam. But that is in the future, when I can buy an aftermarket if there is already a stock one on there.
yes it does,u can use a 92-95 cpi vortec foel pump unit,but i still would get the walbro!
sweeet, sounds like a plan:bigok: :bigok:
make sure u make a project thread and take lost of pictures !
yep like brian said, it has a stock unit on the fuel rails.