Ok in the progress of buying some headers what I want to know if I should go with the 1-7/8 or 1-3/4 from PaceSetter and what's the difference goung on a 04silverado 5.3 crew cab

 

1 3/4 are plenty big for a bolt on 5.3.

 

I agree…..
Generally speaking, if you’re pushing 500 or more horsepower at the flywheel I would tend to say you would be looking at the 1.875” primary tube models and 300-500 hp at the flywheel 1.750” primaries, with anything under 300hp ideally served by using 1.625” primaries. The problem with that is you won’t likely find many long-tube headers in 1.625” for a Gen III/IV equipped vehicle if at all. It won’t make that big of difference to worry about though and will leave you room to grow and besides just about everything from a 5.3L up makes close to that at the flywheel anyway.

 

I agree with bear... but 1.5 may be a little small. What about a Thorley that is a 1 5/8" tri-y design? I think that would be one of the better options at stock power levels.

Basically, unless you see a supercharger in your future, go with the 1 3/4" lt's. They will be better for NA power on a 5.3.

 

You are correct and is exactly what I meant to type. My mind was thinking one thing and my fingers were typing something else entirely.
You are better than spell check..LOL

 

Thanks guys ...maybe a cam dnt know yet on a supercharger its my daily driver