Edlebrock 60917 NHRA head
 

Can someone enlighten me on these heads? It seems the exhaust ports are re-positioned from stock?? Exhaust flanges shortened???
Using these on a Super Stocker and they are causing some real grief.

Re: Edlebrock 60917 NHRA head
 

From the Edelbrock technical instructions:
Exhaust flange has been extended out .125” in order to provide dry exhaust bolt/stud holes.
From NHRA classification, they carry a penalty (weight/ratio HP) for using those heads.
https://edelbrock-instructions-v1.s3...rock/60917.pdf

Re: Edlebrock 60917 NHRA head
 

You can bet that anyone running those heads in SS has that extra flange milled off the exhaust ports

Re: Edlebrock 60917 NHRA head
 

I expect what Mike is saying is....Yes, fully prepared (ported/welded/etc.) SuperStock heads, regardless of origin, probably have had the exhaust ports relocated somewhat, and had the flanges cut down for port volume reasons. Without seeing what you're working with, I'd anticipate that exhaust flange adapters, properly matched to the port center-lines are going to be necessary.

Re: Edlebrock 60917 NHRA head
 

If anyone has a set or two to sell I am very interested. Thanks