I have a 540 inch bbc thats mild,nice heads, 8.8 to 1 comp, 570 lift hyd roller and a single 1050 holley. Right now I am running an eddie marine EMI thunder exhaust. I have heard these are not very good but am I going to get a noticeable gain by changing them. If so which ones do you think would be the best?

I have a simliar enigne. I built a n.a. 540, makes 680 hp. All good parts, AFR heads, 9.25 compression, .600 lift 238* cam, etc. etc.. Anyway, I originally had Gil WetOffshore exhaust on my 454 Magnum. I put that exhaust on this 540. I ended up with a bad reversion problem. The end result was switching to full dry CMI headers. Problem was solved but gained no noticable speed. Maybe 50 rpm, nothing major.

You may want to look into Lightning headers, I put a set on my 25 checkmate back in 90 454 with a roots supercharger made a huge performance gain, but becareful you should check the plugs!! will most likly have to go up a jet size or two!!!!!! I have run them on every motor since then, got them on my cat now with 738 HP NA motors.

Are you located in havasu?? just asking because we have a place in havasu and boat there a few times a year. we live in Michigan (for now) it sure is nice out there!!

CMI IS THE BEST IVE SEEN , I do have a couple of set that are used if interested email me or give me a call

YUP......... go CMI