Really want to buy a 3" downpipe. Let me know what you have

If you have one. How much.

Not sure where this would belong. I have searched but can't seem to find what I am looking for. I would like to know how far from the firewall and how far from the rad. Support a 2JZ sits in a StarQuest with VetteKiller's mounts. I want to swap a 2JZ in my Max if I don't have to do a lot of cutting on the firewall/rad.support. I have my Dad's bass boat to go off of the stock measurements.

Over the last few weeks as the weather has gotten warmer, I have noticed that my car has a difficult time starting. I will drive to work and then let it sit all day, when I go out at the end of the work day to go home, it takes a while for the engine to start and I have to pump the gas pedal a bit. The weird thing is that when I let it sit all night in the garage it starts right up in the morning. Any thoughts?