I'm currently installing BBK L/t's and someone told me that I may want to double gasket them. I was looking at the gaskets and them seemed fine. Is this true or should I be fine with the gaskets provided?

 

I wouldnt use the gaskets provided, they are cheap crap. My headers are leaking because of them. I also wouldnt double gasket them.

 

i used the bbk gaskets. how would i know that they are leaking?

 

You would know if they were, you would hear at the very least a ticking noise.
I used the BBK's because when I ordered my headers they didnt have any Percy gaskets in stock, but they assured me they werent necessary. The shop that I paid siad they use the BBK's almost everytime and very rarely do they have problems. Just make sure you retighten the bolts.
I would guess if you "double" gasket you would only increase the odds of a blowout, use the BBK's or if you are really worried get Percy's gaskets.

 

Get Percys Seal-4-good aluminum gaskets. Most folks here say that the BBK gaskets are almost impossible to seal.