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Discussion Starter #1
Hello all-
I'm wondering if the 2-piece exhaust manifolds from a 90's Spider will work on my 77 Spider the same way the early 70's version does? I'm replacing the entire exhaust, so would those manifolds hook up correctly to an early 70's downpipe? I do not need a catalytic converter.

Are there differences between the 90's and 70's versions size-wise or in performance?

Thanks
 

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the 90's 2 piece 'motronic' manifold has some differences to the early 2 piece....exactly what these are I do not know, but I doubt it will hook up to a 70's exhaust.
2 Piece Exhaust Manifold
 

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Agree. You may have to use S4 secondaries and then a custom collector to hook into the rear section of your exhaust. It is worth doing if you do not have to pass an emissions test. Estimated HP gain between 5 and 10.
 

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Hello all-
I'm wondering if the 2-piece exhaust manifolds from a 90's Spider will work on my 77 Spider the same way the early 70's version does? I'm replacing the entire exhaust, so would those manifolds hook up correctly to an early 70's downpipe? I do not need a catalytic converter.

Are there differences between the 90's and 70's versions size-wise or in performance?

Thanks
Hello, the 90s front exhaust manifolds are longer than the early 70s manifolds .They will bolt up to the motor,but they will be longer than the front pipe.To make your life easier you should try to locate the early manifolds used and install the early 69/74 spider front section of the exhaust.This will help in the long run with no confusion over witch front exhaust to order in the future.GOOD LUCK Paul
 

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@jwise77 , as mentioned earlier, the exhaust manifolds from a Series 4 Spider are different than the earlier 2 piece manifolds and will not bolt-up to the pre 75 exhaust systems. If you are having a full custom system made, no problem. I changed the exhaust on my (otherwise) bone stock 86 Spider to the (older style) two piece system using a early stock front down pipe and muffler (drilled and welded a threaded bung for the 02 sensor), early stock center muffler, and the Stinger (rear muffler delete) rear pipe. No drone, sounds great. 10 hp on the butt dyno.
 

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Discussion Starter #7
@jwise77 , as mentioned earlier, the exhaust manifolds from a Series 4 Spider are different than the earlier 2 piece manifolds and will not bolt-up to the pre 75 exhaust systems. If you are having a full custom system made, no problem. I changed the exhaust on my (otherwise) bone stock 86 Spider to the (older style) two piece system using a early stock front down pipe and muffler (drilled and welded a threaded bung for the 02 sensor), early stock center muffler, and the Stinger (rear muffler delete) rear pipe. No drone, sounds great. 10 hp on the butt dyno.
Yea- I'm going to buy a new stock early 70's exhaust system from the manifolds back. Not planning on a custom system right now. Thanks
 

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Richard Jemison
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No! the late 89-94 exhaust manifolds will not fit correctly to the head of any earlier engine.
The exhaust ports in the manifold castings are smaller in diameter and positioned higher in the casting flange.
The flange will bolt up but there will be serious congestion.

Glad you are buying the early version.
 

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When I transferred my Shankle headers from a SPICA head to a Bosch head I only had to remove a small amount of metal from the header flanges to match the ports which led me to believe that the port positions are not a lot different.
 
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