Best option for 5.7 Mag exhaust replacment?
 

Hey Guys,

I've got a 1990 Scarab 21' with a 5.7 Mag. I've noticed a small crack in the water jacket of one of the exhaust manifolds, so I'm looking to replace the set. Does anyone have any experience with the cheap re-pops out there?

Thanks
-Rob

try this...

http://www.perfprotech.com/store/pro...-NS,75402.aspx

i'd do the cheap manifolds, but go with imco or another quality ss riser...

I just put the Imco Thumper setup on my boat.It was reasonable about 1k a motor and came with everything.

I would take a look at Revolution marine exhaust.

I have used GLM aluminum manifolds with very good results. The internal passages are a split design (separating the exhaust pulses) and the aluminum shaves about 50 lbs off the stern. I paired these these with a set of Hardin/IMCO stainless risers. Very good results... I have about $500 in the whole set up (I bought the risers used).

Tom

tom z did you see any difference in performance with the glm manifolds. any gain in rpm. thanks.

Thanks for the ideas guys!

I think I'm going to end up picking up some factory Merc manifolds.

I see 2 options, ceramic or E-coat.

Merc's site says Ceramic for salt, and E-coat for fresh, is this correct?

Thanks
-Rob

I couldn't tell you. I picked up the boat sans power and built a 383 for it. It was turning 5300-5400 RPM and running 77 on GPS. I have other friends with small block power running the same setup and approaching or surpassing 80. I'd say they work.

Dennis Moore (Small Block and Big Block Marine Performance book author) is behind the design on these.

I have a new cam from RMBuilder going in this weekend. Hoping to add another 800 RPM or so. The exhaust is more than capable of supporting it.

Hope this helps.

Tom

thanks tomz let me know how the new cams work.