What is the disadvantage of putting stiffer springs in?
 

Are there any disadvantages to putting stiffer springs in for a higher redline?

Maybe the cost of doing it, lower MPG because the engine has to work harder, higher idle speed because it may idle rougher??

pretty sure you wont lose anything. You should be able to put the kit in and nothing change other than your truck will stop fueling at 3k rather that 2700. So if you drive it the same as before then i wouldn't imagine any fuel economy changes.

Are you talking about valve springs or governor springs?

depending on which gov springs you go with you could start to float your valve's if you rev it up enough with stock valve springs and retainers.

Thanks, valve springs is what I'm asking about.

there wouldnt be much point to stiffer valve springs if you wernt planning on putting GSK in it to get higher redline..

I posted on the 12v instead of the 24v, so just wondering in general, assuming GSK is in place, what is the down side of using stiffer valve springs?

There is no down side to stiffer valve springs, they just aren't needed if you don't plan on going up past 3200 RPM. If you have 3k gsk you don't need the valve springs, only if you have 4k springs do you need valve springs.

Moderately heavy springs don't have much of a down side, but the super heavy ones are a little tough on the cam lobes on a dd.

but then again if you had the super stiff springs and the mods that required them then it would be highly unlikely that the truck would be a dd anyway:c: