Manifolds on 500HP's.....
 

What is a good but not super expensive replacement for the stock Gil manifolds on 500HP's? Our motors have the original Gils and we want to get some newer ones. We were contemplating headers but I think hey may be a bit to pricey...suggestions please.....

Thanks

CMI Unitops. I had set on my 525SC. Priced about the same as most manifold/riser systems.
http://www.offshoreonly.com/forums/s...d.php?t=156933

Those or a Stainless Marine System.

Also Hardin marine makes some headers and they are called cyclone shortys that work as a replacement for the Gil exhaust

From a performance stand point the good ol' Gil's just can't be beat for a high performance exhaust manifolds. A new set part#420-901180-GB http://www.cpperformance.com/detail.aspx?ID=2578
Suggested list price is 1714.27 our discounted price on these is $1575.00 per pair.

Your best header option would be the "Cyclone" shorty headers. http://www.cpperformance.com/detail.aspx?ID=290
These headers are a direct replacement for the Gil manifolds and will allow you to use your existing tailpipe and sell for $2399.00.

Look at Stainless Marine

Exhaust
 

Captain Chucky

Keith Eickert performance products sell both the Gils and the Hardin Cyclones. I do have a few questions real quick. Are you looking at replacing the manifolds and risers or just manifolds? Have you done any up grades to the 500's? If not are you planning on doing any up grades? If you are going to keep the hp 500s the way they are you really can't go wrong with one or the other but if you want to do any up grades the Cyclones are the way to go. As far as pricing goes the Gil manifolds are $1575.99 for the set and if you want the manifolds and risers they are $2399.99 per set. The Cyclones are $2200.00 for the headers and for the headers and risers it would only be $3495.99. I am here to help any way I can. You can call us at (386) 446-0660 or e-mail me at [email protected].

Sincerely

Tony

ditto

Thanks for the info guys. I do have a set of Stainless Marine manifolds and risers from another engine I bought last year but I was told by an engine builder they are not much better than the stock Gils. Based on his opinion I started looking at CMI.
I am going to check out the unitops now. Thanks for that info Griff.


Chuck

Chuck -

Please email me at [email protected] I tried returning the PM you sent, but my sent folder is full and i cannot clear it or reply. Sorry about the delay.

We can get you into Unitops providing you have a standard bravo exhaust layout for about the same cost as good manifolds and risers. A true header at a manifold price.

All the guys that answered here have very good products. So do not take this as a knock on the competition.

Kirk

Sent you am email Kirk. Thanks.

Like KEPP posted, if you plan on leaving the engine stock, there is no reason to buy a header system. You won't see any hp gain. If manifolds are cheaper, stay with them.

Unless you want some bling.. :-)

Jeff....I do plan on upgrades for the 500's. We are going with a bigger cam and better valves for now. Next year we will probably do more upgrades to them. If I can get headers for the price of manifolds I'm in. Besides who doesn't like more bling???:D:drink:

:ernaehrung004:
Chuck

Give Brownie and call at Stainless Marine. I think you'll be surprised at what you can put thru their stuff.

Actual headers will also make changing spark plugs easier.

You will be fine with the headers, even if you add blower!!

The 500 Whipple is set up for stock exhaust. Stock exhaust on the later 500 is an Etop!!

I hear you on the bling. Some advice, the first thing I would do to that engine is either new heads, or work the current heads. They are a big limiting factor. I think you will be disapointed with just caming it up, and no head work. I have a buddy who has just gone through all this. Rebuild hos carb 500, new rotating assembly, little better than stock, higher compresion, bigger cam, bigger carb, he only gained 2 mph. when up 1/2 a pitch prop. The heads are his limiting factor. No sence buying headers when the heads don't flow good enough.

My 2 cents.

Call David Wade Marine in Baton Rouge. I dont know if he still has it or not, but he had the cig that went in the woods a couple years ago on the tf200. The motors were fried but I believe they were hp500`s. you may get a good deal on used parts

CJ I am thinking of putting some Dart heads on the engines. Do you think that would be a good choice? I have a set already so I would only need to buy 1 more set.
I have a 540c.i. Bowtie engine that I may start to cannibalize. The 540 is down to the short block so the parts are readily available. To many options in to little time with not enough money = a big effin headache!!!

Chuck

Thanks bro! I will give them a call first thing Monday morning.
Take care!
Chuck

I am still draggin azz on this manifold issue. Can anyone give me some input on Imco Powerflow manifolds? Are they any good? Thanks guys.

Chuck

They are fine, but they do have wet joint between the riser and manifold. Gils probably flow a little better. Also, you would probably need a new bracket for ALT/PS. I did when I put Imco's on my 454mag.

Thanks Griff..... The search continues.....:cool: