Intake Sealing Question
Thread Starter
Intermediate
Joined: Oct 2004
Posts: 36
Likes: 0
From: NEW MEXICO
Intake Sealing Question
I just pulled my original intake to reseal the rear. The Felpro gasket set came with a restrictor. Based on the instructions it would appear it should go on the right side (center). However, the gaskets that came off have the restrictor on both sides (they have only been since the rebuild, not by me, - about 500 miles). The old gaskets and the new have the exact same number.
Is the restrictor necessary, and if so, which side and what is the purpose? I have searched many previous posts on intake sealing and found nothing mentioned about the restrictor.
Thanks in advance for your help!!
Is the restrictor necessary, and if so, which side and what is the purpose? I have searched many previous posts on intake sealing and found nothing mentioned about the restrictor.
Thanks in advance for your help!!
Last edited by 4ME+N73; Mar 15, 2005 at 03:21 PM.
Burning Brakes
Joined: Nov 2000
Posts: 948
Likes: 0
From: Johnston Iowa
I do belive these are heat riser ports. If you are using a newer intake manifold that does not use these ports I do believe that the restrictors should be installed on both sides. Maybe someone else will chime in to confirm this so do not hold me to it.
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
GM used restrictors differently over the years. The gasket sets come with both, you are supposed to add/remove them as required. Per David Vizard's book (1978 edition):
55-72 used no restrictors
73 restricted left side except HD (3/4 ton and up) use no restrictors
74 2bbl restriced left; 4bbl restricted both, except HD use none.
75 restricted left, except HD 2bbl both open, 4bbl both restricted
76 4bbl no restrictors, 2bbl and Calif restricted left, HD 2bbl both open, HD 4bbl both restricted
77 restricted left side, except HD 2bbl both open, HD 4bbl both restricted
Joe
55-72 used no restrictors
73 restricted left side except HD (3/4 ton and up) use no restrictors
74 2bbl restriced left; 4bbl restricted both, except HD use none.
75 restricted left, except HD 2bbl both open, 4bbl both restricted
76 4bbl no restrictors, 2bbl and Calif restricted left, HD 2bbl both open, HD 4bbl both restricted
77 restricted left side, except HD 2bbl both open, HD 4bbl both restricted
Joe
