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 1/4" piping
-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
RH manifold "Z", Thornton part