nitrousnolan

Ok I have a 93, 35 Fountain I am repowering from top to bottom, I built a set of Dart 540's opened up to 557ci with Afrs(315)'s . Motors have not yet been to the dyno but expect to see 625hp or so NO BLOWERS just NA. I think I am going to buy CMI headers and just wondering if you think I need sporttube headers or if the E-Top would do me ok. There is about $1500 difference between the two. I appreciate your advice in advance Thanks.

getrdunn

iTrader: (7)

With the power menitoned if your going CMI the Etops would be fine. I would look into a few manifolds / headers before dropping the big dollar. You probably have however from your recent post it sounds like your turning up the wick a bit and you may get the same results for a lot less money. There are many out there however I think for the money the lightenings and Dana's are pretty hard to beat. The CMI's are impressive though.
Good luck!

jrz

On a NA engine of that CI, the longer primary headers may be the better choice. The OEM's are not using the longer headers for the bling.

Brad Zastrow

The Sport Tubes look better and might give you a little more power. The E-Tops are great choice and would still give you the looks and the power difference may not be worth the extra moeny to spend on Sport Tubes. Manifold style headers are ugly. BLING it with CMI!
Ateco is a distributor for CMI.

LAKECHAIN

I had Eddie Marine headers and switched to CMI E-Tops, I noticed stronger mid range power. Picked up about 3 more mph. Got a good deal from ATECO

AIR TIME

ugly maybe its all in the eye of the beholder, plus my stainless marines have out lasted my friends 4yr old cmi e tops by 4yrs his leaked . and the gen3s grow on you after a while and you can custom paint the manifolds , and are under 3400 for 5''. now thats cool looking to see 5'' pipes coming out the trans instead of 4'' sport tubes or e tops cool: but if you must go with cmi go sport tube it will help your NA motors AND IF YOU GO IN SALTWATER FLUSH THEM OUT.either pair that is.

RaggedEdge

The E-Tops are a great, put them on my 525 SC's for seven seasons with no problems at all. I have the Sport Tubes now on these 525's and hope they work out as well. I have to believe that the Sport Tubes make more power with the longer primary tubes, especially on a NA motor. I don't think Merc would spend the extra money if that were not the case, and they used the E-Tops for years on the 500 EFI's. I think I remember hearing that Merc Racing had worked with CMI on the Sport Tube design specifically for the 525's.

Not to mention they look cool as he!!. Did you check out the used ones on Shogrens site?

GPM

Put those E tops on the flow bench, I doubt you'll be impressed.

jrz

Does the flow bench float?

BenPerfected

My testing on NA 500 CI was the Sport Tubes made about 15 HP more than race E-Tops (5" OD) at higher RPM. The standard CMI Sport Tubes are available with 4.0" ID X 4.5" ID stepped tails as an option if you want 5" OD pipes at the transom. On a cost per HP, $1500 for 15 HP isn't out of line on engines that are already at 625 HP.