Gang I know this subject is beat to death however I just want to be certain I'm not making a mistake.
I have an 05 with 48k. By all accounts it appears to have been very well maintained. Will a 65mm overstress the SC or motor? I don't race or drag, I just love power at the pedal when I want to blast off.

PS, I am adding a custom DCAI. At the radiator support, is a 3" the maximum or is there enough surface to drill 4" hole on both sides?

 

There are members with a lot of miles on their smaller pulleys with no issues.. Be sure to have the NeedsWings Coolant Isolation Kit, their intake manifold gaskets and pulley saver kit.

Now which 65mm pulley to go with is debate-able. I personally would not go with an aluminum one.

 

There is no need to go to 4 inch, the 3 in DCAI will flow more than you can use!