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#1
02-26-2018, 06:26 PM
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Standard exhaust manifolds
Are the standard low hp GTO exhaust manifolds interchangeable throughout the years? 4bbl vs tripower or 67 4bbl on up. Are their outlets different diameter? Not worried about casting numbers.
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#2
02-26-2018, 07:19 PM
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The short answer is yes. There were different configurations that were on some years of big cars and F-body. But the basic rear dump log manifolds are functionally the same across years and engine sizes. The manifolds on a tri-power GTO are exactly the same as the ones on the same year 326. They could also be swapped on to a 350 or 400 or 455 in an A-body up through the late '70s.
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1966 GTO 1969 Lemans Convertible- F.A.S.T. legal family cruiser. 12.59 on G70-14 Polyglas tires. 1.78 60' 1969 Bonneville Safari- cross country family cruiser. . 1979 Trans Am 400, 4-speed, 4 wheel disc. View from the drivers seat racing down Atco Raceway- http://www.youtube.com/watch?v=GhYDMdOEC7A Ride along in the other lane-http://www.youtube.com/watch?v=mIzgpLtF_uw |
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#3
02-26-2018, 09:35 PM
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My confusion was I saw on the Wallace Racing the same casting number manifolds used on motors that were supposed to have 2"headpipes while others had 2 1/4". Were the 2 1/4" necked down to fit. This info has departed my brain thru the years and you just can't go out and order them anymore.
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#4
02-26-2018, 10:44 PM
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The standard log manifolds will accomodate both pipe sizes.
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1964 Tempest Coupe LS3/4L70E/3.42 1964 Le Mans Convertible 421 HO/TH350/3.08 2002 WS6 Convertible LS1/4L60E/3.23 1966 VW Type 2 Single Cab Pickup 140hp 2276 1956 VW Type 2 Panel Van 36hp 1200 1957 VW Type 1 Beetle 180hp 2276 |
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#5
02-27-2018, 12:17 PM
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also please don't forget that there are some two stud, and three stud manifolds;
I believe that somewhere around 1973/4 they revised them to have three studs on each side... (please correct me if I'm wrong!!) Also, I believe it was the full sized cars that had one of the manifolds which had a center dump - all of the manifolds I have had were F-body or A-body style manifolds.
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1970 Formula 400 Carousel Red paint on Black standard interior A no-engine, no-transmission, no-wheel option car. Quite likely one of few '70 Muncie three speed Formula 400's left. 1991 Grand Am: 14.4 @ 93.7mph (DA corrected) (retired DD, stock appearing) 2009 Cobalt SS: 13.9 @ 103mph (current DD; makes something north of 300hp & 350ft/lbs) |
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