CLASS RACER FORUM - View Single Post

SDT1DYI · 05-06-2021, 10:18 PM

They are legal so long as the runner volumes meet the OEM stated requirements. 165 CC SBC intakes are difficult to get down to. 161 CC is near impossible.

RHS heads I don't believe are manufactured any longer?
Hard to understand how some of these heads become approved by NHRA when in fact none actually "in a out of the box condition" are legal.
So a lot of machining and innovation is necessary to get them to pour correctly.
Making it expensive compared to using a good condition OEM casting and you then have no HP penalty.

Steve Teeter STK/SS 620

05-06-2021, 10:18 PM	#6
SDT1DYI Member Join Date: Nov 2016 Location: Indianola Washington Posts: 401 Likes: 0 Liked 453 Times in 146 Posts	Re: replacement Stock heads They are legal so long as the runner volumes meet the OEM stated requirements. 165 CC SBC intakes are difficult to get down to. 161 CC is near impossible. RHS heads I don't believe are manufactured any longer? Hard to understand how some of these heads become approved by NHRA when in fact none actually "in a out of the box condition" are legal. So a lot of machining and innovation is necessary to get them to pour correctly. Making it expensive compared to using a good condition OEM casting and you then have no HP penalty. Steve Teeter STK/SS 620