There is a pair of new headers offered locally. Seller says they fit Olds 455. I am interested in them for my 69 olds 98 with a/c. Seller also says they fit 350 403 & 400 engines. Anyone know if these will definately fit my car?

 

First of all, the seller is an idiot because the headers for the 350 and 403 small blocks don't interchange with those for the 400 and 455 big blocks. Second, they won't fit anyway because the 65-70 full size cars (Eighty Eights and Ninety Eights) have a "rear steer" design where the steering linkage is behind the crossmember. Those headers are for the front-steer Cutlass line.

 

Joe's right, If you want to run duals Thornton sells the correct "S" manifold that humps over the gear box and back down to run the duals correctly, you can cap off the crossover on the pass. side or get the "Z" manifold instead. I got them for 69' 98 just gotta get to putting them on

 

I can vouch for the Thornton S manifold. I got one for my 66 Dynamic and it fits nicely in there. I can't imagine a cleaner way of running the exhaust. If you did get it I'm sure you'd be happy with the results.

-Rich