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7.4 to 525sc swap exhaust problem

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Old 12-14-2006, 01:36 AM
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Default 7.4 to 525sc swap exhaust problem

I swaped a 7.4 mercruiser to a 525sc in a 1997 Mariah 25'. all is going well but I have a problem with the exhaust. The Gil manifolds or risers do not line up with my existing exhaust.( I sold the old lady on the sc motor but she's not willing to lose the silent choise) What i am wondering is : Is there a riser that will work with my Gil manifolds and has the same (or close to same) exit position as a stock mercruiser 7.4. this seems like the easy fix. but i am open to sugestions. THANKS
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Old 12-14-2006, 01:41 AM
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Default Re: 7.4 to 525sc swap exhaust problem

Yes, contact cpperformance.com and you can order the correct risers
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Old 12-14-2006, 01:54 AM
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Default Re: 7.4 to 525sc swap exhaust problem

I would like to find a used part or another option first ,before I go that route. but your right CPP is a great source. thanks
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Old 12-14-2006, 07:48 AM
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Default Re: 7.4 to 525sc swap exhaust problem

Getout your chop saw and wekder. Actually I shortend some used, Gil/trs risers. I made 2, 45* cuts then twisted the pipes untill I lined up with the Bravo tips. I made a magic Marker line on the pipes, brought them to a friend to TIG weld. I heated the inner pipe,at my first cut, and drove a wedge into it to expand the inner pipe out to the outer, leaving enough gap to equal the holes that Gill had to let the water enter the exhaust stream.They worked great.
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Old 12-14-2006, 07:53 AM
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Default Re: 7.4 to 525sc swap exhaust problem

nice job !
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Old 12-14-2006, 08:27 AM
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Default Re: 7.4 to 525sc swap exhaust problem

You can all make aluminum wedges and short riser blocks to make adjustments. I made a pair of wedges for my boat, about 1 1/2" on the big end sloping down to about 3/8" on the short. Worked very well, they run a bit warm but not to bad.
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Old 12-14-2006, 09:35 AM
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Default Re: 7.4 to 525sc swap exhaust problem

Gil sells wedges for up/down adjustment. They go between the manifold and S/S riser. They were kind of pricey so I had a machine shop make a set of 4 for about $50.
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