65GS.com - Buick Gran Sport Enthusiasts!
Classifieds => Parts For Sale => Topic started by: gs spoken here on November 21, 2015, 02:44:58 PM
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Like new Offy 2X4 401/424 intake. Will trade for 3X2 or 2X2 intake for 401 or will sell for $200.00 plus the shipping. I know these do not flow as good as stock ones, but Centerville Auto Repair, ( Russ Martin) can fix that, see below. New Offy is $443.00 from Summit Racing. With this one and the fixing you will have about the same $ as a new non fixed one. Thanks Bill.
Fixing the Offenhauser intakes
The Offy intakes that are made for the nailhead are VERY restrictive, (all 3x2 and 2x4 Offy intakes) if you use one without our repair service you will lose about 50hp over a stock 4 barrel! We spent many hours on a flow bench to figure out how to fix these. There are 4 restrictions that must be opened up.. The top two are easy, you can see how we milled a slot between the ports. The other two are inside the intake requiring small holes to bored on each end to get a tool inside and open up the other two passages. In stock form one front cylinder and one rear only flow about 90 cfm each, two others flow 120 and the remaining 4 flow at 165 cfm .. When we are done with your intake all cylinders will be more balanced with ports flowing from 160 cfm to 175 cfm .. There will be a 3 week turn around time and it will be hard to see where we made holes for the repairs..The cost is 200.00 plus shipping.