BBC Cylinder Head Casting #'s

mannymen · 09-30-2009, 10:23 PM

Are there any differences (intake/exhaust volume) between the BBC 840 head and the 391 head? I don't see the intake/exhaust runner size for the 391 head on the NHRA website, but it's listed in the engine blueprint spec guide.

Thanks
Manny

Dwight Southerland · 10-01-2009, 01:00 PM

For a Stock class car, the 391 head is not as good as the later superceded heads, so there's no good reason to use them. For SS, the castings in the late 291 heads offer a tremendous advantage, especially for the weld & grind industry, so there's no reason to use them there, either. That's probably why no one has gone to the trouble to have them poured for volume in the last 20 years.

09-30-2009, 10:23 PM	#1
mannymen Senior Member Join Date: Apr 2003 Posts: 728 Likes: 5 Liked 13 Times in 7 Posts	BBC Cylinder Head Casting #'s Are there any differences (intake/exhaust volume) between the BBC 840 head and the 391 head? I don't see the intake/exhaust runner size for the 391 head on the NHRA website, but it's listed in the engine blueprint spec guide. Thanks Manny __________________ N/A

10-01-2009, 01:00 PM	#2
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,996 Likes: 63 Liked 756 Times in 189 Posts	Re: BBC Cylinder Head Casting #'s For a Stock class car, the 391 head is not as good as the later superceded heads, so there's no good reason to use them. For SS, the castings in the late 291 heads offer a tremendous advantage, especially for the weld & grind industry, so there's no reason to use them there, either. That's probably why no one has gone to the trouble to have them poured for volume in the last 20 years.