What is limit you could go down to on a 5.3, and still be daily driver friendly? The Magnuson supplied one is 3.4. Could you go as low` as 2.9, 3.0?

 

I ran a 3.25" pulley with my 5.3 on the street with good results,I also ran a 3.0",but saw very little increase in power with the 5.3 so i switched back to the 3.25".With my 403 I'm running a 2.75"pulley,but would'nt recommend it with a 5.3.

 

Did you retune foe the 3.0?

 

No,I didn't tune for the 3.0" and was afraid I wasn't getting enough fuel,so I switched back to the 3.25"with was giving 9 1/2lbs of boost.

 

Wow!! 91/2 pounds! Yikes!! Looks like I'll probably retune for the 3.2, too! So...you thought you might be running out of fuel? Pump, or injector, or both?

 

At the time I was suspisous that the fuel pump was a problem.I was running the original MSD boost-a-pump setup with the stock fuel pump and had just replaced my second fuel pump.Now I'm running a big Edelbrock inline fuel pump along with the stock pump and 57lb injectors,but I'm running 403 cid.

 

I have an 04, with the Wallbro in-tank pump that Magnuson supplies. Think that would be enough? I'm looking at approx. 59-60 idle, and 56-58 at wot. That's fuel pressure, obviously.

 

You should be fine with that setup and your 42lb injectors should be big enough run either a 3.0" or a 3.25" pulley,I'd go with the 3.25"my truck made 417rwhp with the the 3.25"pulley and about the same hp with the 3.0"with only a slight gain in torque.The 3.25" pulley is close to optimum with the 5.3,you start getting deminishing return after that.

 

Alrighty, then. Thanks for the info. 'Preciate it!

 

Get Er Done Bill