i want a true dual flowmaster super 40s. is this possible since the whole rear left of truck is taken up by gas tank?

 

Yes. Both pipes will run down the passenger side of the truck. The mufflers will be installed on their sides next to one another.

 

so, you can cut the exhaust into true duals behind the second set of cats?

I have a 2001 F-150 4.6 and it has four cats. Would true duals make much difference in sound volume and tone? I wouldn't think it would unless you removed one pair of cats or added high flow cats. Isn't it those four cats that make my truck so queit in the first place?

 

mine only has 2 cats

 

A 2002? I highly doubt you only have 2 cats unless you have taken a pair off. All of that generation of F150 has 4 cats.