is it worth changing exhaust on a pro- charged 502 mag efi running 5lbs of boost ? talked to different engine builders some say more air in needs more room to go out ? will the system run just as good with stock exhaust ? should i save my $$$ and just put it toward pro - charger or buy exhaust first ? any opinions

Well 26sonic, I was asking myself the same question about 8 months ago. What I have concluded is that if money is not a problem, get both. I am in the process of getting a whipple, hydraulic steering and an XZ drive for about 10,12,,14; Well I don't want to know what the total is. In my conversations with Dustin Whipple he has stated that I would only gain probably 15 hp with powerflows. That is only about 1 mph for around $1600. You could probably gain 30 or 40 with headers and ECU reprogram, but they cost even more. So for me that wasn't enough. I wanted 10-15 mph increase not 2-4. It seems that the exhaust is more important with larger motors and naturally aspirated motors. It's all about speed cost money, but I think dollar for dollar, a super charger/ blower will give you the best bang for the bucks. However, you have to be prepared for the extra HP and speed. Steering for you and your families life, and drive (hopefully strong enough) for less maintenance problems. It is a vicious cycle and there is no free lunch. Oh yea I forgot about the Lab prop, man this is getting expensive fast.
So, I didn't answer your question. I would save the money for the Pro-charger and get the exhaust later. My .02 ,just be safe!

If you install a ProCharger, Exhaust is not an Issue. When i had my 22Zx I ran 63MPH top end after I added the ProCharger I was running 80-82MPH I changed my exhaust to Stainless Marine and top end was 80. When I hit the switch down to Capt Call silent exhaust I went back up to 82. ProChargers like air and not out. I would go with the Procharger if your hours are not high on your motor.

Merc exhaust is good to about 600 hp. You do not have to change the exhaust.

thanks guys , called pro charge today they said the same thing , the stock exhast is fine .

I made 744HP thru stock exhaust but they only lasted 2 years. Putting on EMI.

I run a 502 MPI procharger on my boat, I also run an EGT gauge. I didn't like seeing the high eg temps, So I put some Gil's on. The EGT's dropped 150º. It's true that boosted engine's don't need the High end headers NA engines do. But a better flowing exhaust will get out more of the cylinder heat associated with supper charged engines. If you call back Procharger and asked them if better flowing exhaust would be better. They will say yes. The answer they gave you is ."It's not needed" But just ask them if it will be better. They will say yes. I know this because I've asked that question. good luck