Exhaust advise??!!!???
#1
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Joined: Jul 2005
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From: Spokane, Washington
Many of you know I have been working on my Scarab for a couple of years. I have now gotten to the point where I am fixing all the shortcuts I have taken in the past. The biggest mistake so far had been the exhaust- when I built the engines a couple of years ago I cheaped out on the exhaust- I had to cut corners somewhere- so I blasted the stock manifolds and painted them which was a bad idea. Now I am asking this question- yes this is a performance boat, but, I am not looking to go faster, I am just looking to go. So now I have to replace my exhaust and I am looking at all my options-
Here is what I did to the engines a couple of years ago-
4 bolt main blocks, balanced, with forged pistons, bored 60 over, rec port heads with air gap manifolds and 750 holleys. For ignition all I have is pertronix flame thrower coil and a mallory unilite distributer. Do I need headers, is it really worth 4 grand, or even a couple of grand? Or should I just buy GLH stock replacements and call it good? Does anyone have any experience with these? Big difference in $600- but I also know you do get what you pay for. Any advise is always appreciated
Here is what I did to the engines a couple of years ago-
4 bolt main blocks, balanced, with forged pistons, bored 60 over, rec port heads with air gap manifolds and 750 holleys. For ignition all I have is pertronix flame thrower coil and a mallory unilite distributer. Do I need headers, is it really worth 4 grand, or even a couple of grand? Or should I just buy GLH stock replacements and call it good? Does anyone have any experience with these? Big difference in $600- but I also know you do get what you pay for. Any advise is always appreciated
#2
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Joined: Apr 2005
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From: San Diego, Ca
Scott..
Buy some used 496ho exhaust manifolds...They will work great and bolt right up...Plus they are much lighter than your current exaust. Should be able to buy a pair for about $300 a set. This IS the route I am going to go next year when I replace mine....
PS..they look cool and the stanless riser can be polished out
Also they can be ported to pick up a few extra ponies
eddie
Buy some used 496ho exhaust manifolds...They will work great and bolt right up...Plus they are much lighter than your current exaust. Should be able to buy a pair for about $300 a set. This IS the route I am going to go next year when I replace mine....
PS..they look cool and the stanless riser can be polished out
Also they can be ported to pick up a few extra ponies
eddie
#3
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Joined: Jul 2005
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From: Spokane, Washington
Scott..
Buy some used 496ho exhaust manifolds...They will work great and bolt right up...Plus they are much lighter than your current exaust. Should be able to buy a pair for about $300 a set. This IS the route I am going to go next year when I replace mine....
PS..they look cool and the stanless riser can be polished out
Also they can be ported to pick up a few extra ponies
eddie
Buy some used 496ho exhaust manifolds...They will work great and bolt right up...Plus they are much lighter than your current exaust. Should be able to buy a pair for about $300 a set. This IS the route I am going to go next year when I replace mine....
PS..they look cool and the stanless riser can be polished out
Also they can be ported to pick up a few extra ponies
eddie
Next question- where do I get a couple of sets?
#5
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Joined: Sep 2007
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From: Toronto, Canada
I was lucky and found Gils on the site for about the same price, but I understand they aren't a favourite amongst the salt-water boaters...plus there are risers on eBay for 496 exhaust for $200/pr....good luck!
#6
I got mine by posting in the "wanted section" , also seen a few sets on ebay in the last couple months
i'v heard the GLM manifolds have issues with the castings , dont bolt up flush without a little help , but thats just what i'v heard
i do know the 496 manifolds are a great improvement over stock , if you take the restrictor plates out of them (they call them turbulators or something like that) they sound fantastic too
next project is to buy an extra set of risers and see if i can polish em up for that aftermarket look
i'v heard the GLM manifolds have issues with the castings , dont bolt up flush without a little help , but thats just what i'v heard
i do know the 496 manifolds are a great improvement over stock , if you take the restrictor plates out of them (they call them turbulators or something like that) they sound fantastic too
next project is to buy an extra set of risers and see if i can polish em up for that aftermarket look
#7
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Joined: Jun 2007
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From: Leonard, MI
Scottie 150 - What year are your engine blocks? I ask this because I too would like to upgrade and the 496 manifold and riser option sounds pretty good. My boat is a 1989 Scarab Excel 31 with the stock 454's. I like the idea of both engines with new exhaust for a grand and not 4 grand! Sounds like there needs to be a few pair for sale now that we all may be looking. You have first dibs on any that come up for sale I will be looking in the fall and next winter.
#8
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From: Spokane, Washington
Mine are early 80's Mark IV- I found a set of 496HO manifolds and risers on my favorite place(EBAY) and bought the other set from Teague Custom Marine. I will let you know how it comes out- should have one of the sets this week. I think I found a place to get some more- but I promised Westcoast he could be the broker-
#10
I just finished mine last month , i think it came out great
its a gen 4 454 , the exhaust sounds great and really kicks up the midrange power over the stock cast iron
not to mention it looks really good with the shift bracket and ign module relocated off the engine
make sure you go for the aluminum if you can , might as well drop weight too
its a gen 4 454 , the exhaust sounds great and really kicks up the midrange power over the stock cast iron
not to mention it looks really good with the shift bracket and ign module relocated off the engine
make sure you go for the aluminum if you can , might as well drop weight too


