Guest Posted March 12, 2002 Share Posted March 12, 2002 I need a 425 intake manifold for my 66 401. Reason? I have a quadrajet I want to fit to my Electra but the original manifold only fits a carter 'slightly-spread-bore' carb.<P>Or, if anyone has an adapter (or can point me to one) to allow a spreadbore carb to fit my 401 intake that will be even better.<P>Does anybody know what other differences there are between the 2 intakes (e.g. port size) then I'd appreciate the info.<P>Thanks<BR>Ozzylectra<p>[ 03-12-2002: Message edited by: Ozzylectra ] Link to comment Share on other sites More sharing options...
Guest Posted March 13, 2002 Share Posted March 13, 2002 I have a Q-jet intake off of a 425. One of the ears was broken. Had it welded and machined, the intake works fine. I would like $75.00 plus shipping (heavy) and handling. e-mail lcrum10037@aol.com<P>'57 Special Link to comment Share on other sites More sharing options...
Guest Posted March 13, 2002 Share Posted March 13, 2002 Question for the group - What manifold was used for the 66 Skylark GS with the 340 hp Qjet option? Was it simply a 425 intake or was it special made for the 401? Link to comment Share on other sites More sharing options...
Guest Posted March 13, 2002 Share Posted March 13, 2002 To the best of my knowledge the 401/425 use the same intake manifold. The difference is the spread bore or square bore carb. mounting. '66 was the first year for the Q-jet, the last year for the nailhead.<P>'57 Special Link to comment Share on other sites More sharing options...
Guest Posted March 13, 2002 Share Posted March 13, 2002 Thanks '57. I've sent you an email.<P>Can someone please confirm that the 425 Intake manifold is a direct bolt on to my 401 nailhead block? Shipping a 40lb intake manifold half way across the world only to find it doesn't fit is going to be a real downer.<P>Does anyone know if there are any other differences? Are the runners larger in diameter or shorter in length? Is the design of them different in some way? I've tried searching for these answers but I'm still unsure where all the good information is on the 'net. Some one I was talking to suggested that I should notice a real performance increase by using the 425 manifold.<P>Thanks<BR>Ozzylectra<p>[ 03-13-2002: Message edited by: Ozzylectra ] Link to comment Share on other sites More sharing options...
Guest Posted March 13, 2002 Share Posted March 13, 2002 ABSOLUTELY, 401/425 MANIFOLDS CAN INTERCHANGE .BOLT PATTERNS ARE THE SAME JUST DIFFERENT PART #S. I JUST BOUGHT A 425 MANIFOLD FROM CARS FOR MY 401 ,BOLTED RIGHT UP.THE INFORMATION IS IN MY GM PARTS INTERCHANGE MANUAL 1950-1965. ONE OF THE BEST BOOKS I EVER PURCHASED AND I RECCOMEND IT TO ANYONE RESTORING A GM 1950-65. GOOD LUCK Link to comment Share on other sites More sharing options...
Guest Posted March 13, 2002 Share Posted March 13, 2002 Thanks for that Rivirider, I'll get the book.<P>You da man. Link to comment Share on other sites More sharing options...
Guest Posted March 14, 2002 Share Posted March 14, 2002 Everything in 1966 except the Riviera came with the square bore carb. The Riv came with the Q jet. The Q Jet might have been a option also in late 66 but I have never confirmed that.<P>The two manifolds are inter changeable. Link to comment Share on other sites More sharing options...
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