I have a 5.3 blower cam with shorty headers.

 

I have a 4.38" and swear tonight I hit 8-9lbs with D1sc and shifting at 5600 on my 5.3. Im running 60lb injectors also. You should buy my 4.75 until you get the boost gauge mounted. Ive learned that to many things affect boost thats why these pulleys have size numbers not boost numbers on the face of them.

 

How much for the 4.75.

 

A 4.2" will drop to 6lb ,but if I were you I would get bigger injectors than drop boost.

 

Man i would like to but right now im low on cash to buy some 60lbs.

 

Pm sent

 

Are you sure your not running out of pump? Just cause your injector duty cycle is that high doesnt mean your out of injector you could be having a big drop in fuel predssure I would get a fuel pressure guage on it as well. What fuel pump u running?