top of page
Custom High Flow 455 Dual Exhaust Manifolds

You asked and we listened!

Brand new castings of the original 1970, 1971, 1972 W30 exhaust manifolds W&Z. Our Thornton Reproduction custom brings you this this larger version. With a larger body overall, and larger ports, you can expect better flow and better performance. Larger exhausts can be used with these. These W&Z's were made for 2 1/2" exhaust pipes.


-These will fit Oldsmobile engines in A body, G body, and B&C body 1970 and newer. Made for big block Oldsmobile 400, 425, 455 with dual exhaust. For small block engines, consider our 350JR's or our shorty headers.

-They were also used on 1969 big blocks; the difference is that in 1969, the left manifold had a heat riser. Some cars up to 1969 have the steering box in the way, and the only option for dual exhaust is our set of GM S&W manifolds.

-If you are looking for performance gains for racing then stick with long tube headers. These are not made for racing; they are made for better flow and to offer another option that performs better than the stock manifold performance.


Highly detailed for show quality restorations.

LH manifold "W", Thornton part #HF21455L.

RH manifold "Z", Thornton part #HF21455R.


Custom High Flow 455 Dual Exhaust Manifolds


    Related Products