That are the casting numbers for HP BB manifolds?

I do not have the #'s memorized but they would be either in the archives or for sure over at www.bigblockdart.com

if its in the archeives i cant find them.

I know big block dart has em

i am looking there and cant find it either.

click on "tech pages" at the top of the page then in the exhaust section click on "b body hp manifolds"

it list 2 sets of manifolds being used on an a body, but doesnt list the original applications.

I know that the 3992 and the 6900 are 68-70 BB HP ones. that's the extent of my knowledge on them. If nobody else chimes in Tom Swope at accurateltd whose email was over there might be able to give you more specific info.

Umm, 3992 and the 6900 are 68-69

70-71 are 2951865 and 2899879

2899879 RH

2951865 LH

thanks guys.

Do the 68-9 & 70-1 flow the same & is the only difference the external bosses on the later ones to mount the heat stove?

The flange orientation is slightly different on the B-Body Big Block Manifolds. Why? I couldn't even fathom the thought process there! The LH side might be interchangeable, but I know the RH side is not if you are using stock head pipes.