Ok guys. Going to stick with my 525sc's. I had to rebuild one last year and we upgraded all components. New roller cam, pistons etc. We are going to freshen up the other engine. of course the newer one is making quite a bit more horsepower than the older one. I am going to try to get the most out of these motors for the next few years. It has stock exhaust and my engine builder suggest I need to get a better set of exhaust, headers that would be a step in to the right direction. What do you guys recommend? It will be a work in progress. After I do this I am going to work on the props and so on.

I put imco powerflow's on my 420's and the quality was excellent. Hindsight if I had to to it again I would go with Stainless Marine. Something with a dry joint from the manifold to the riser would be appealing. Headers are over rated at that power level.

The stock Gil exhaust is fine for what you have. I doubt you'll see any increases with headers.
I switched from the Merc Gil's(cracked) to CMI's on my 525sc and didn't see any gains.

I put Lightning headers on mine. They look good and are maybe a little lighter. I thought I would see a performance increase over the Gils but I could not tell any difference. If the Gils are in good condition, I would just run them.

They are in good condition. Just trying to get a little more speed out of her. This spring I will take notes on my speed and RPM and get my props worked. She runs 81.5 and I don't think that's terrible for a small step 38 Lightning.

If you want to sell the stock ones let me know

Keep the GIL exhaust. There are much better ways to gain power with that combo. Id spend money on a blower upgrade if you want speed increases.

call Dave from imco have them on my motors they work good