im getting mixed opinions, on what exhaust to use on my 500hp carb motors with a 741 cam 236/244 @.50 on 112 so i dont have reversion problems. was looking at the hardin marine cyclone short header a direct replacment for gill manifolds but have had good and bad reviews on them as well, looked at emi thunder talked to them they say no different than my gills. ant one running this set up what exhaust are you using.

Thanks Rick

I really think you'll be fine with the Gils and tall risers. Avoid prolonged idling in gear. Keep the rpms in 800-900 range.

The hardin headers won't help. You're still using the same riser and the water dumps in the same place.

Problem is i no longer have my gill manifolds , just the risers

I'd like to know about this for my future project. What about the Lightning Dry headers? Wouldn't that cure all the issues?

I replaced stock Merc Gils in kind from Douglas Marine, good price. 1/2 the cost of the Hardin shorties.

I'm running the EMI Thunders with a modded long tail riser. what's your compression?

I have same cam as you and am using cmi's. After 2 years I did a freshen up on advice of a friend. I had no problem. many more years have now gone by and still do not see a problem.