Our very own Thornton design; a direct replacement for an exhaust manifold.
These headers are polished 304 stainless steel, with a 1/2" thick steel flange, to prevent warping. 
Option for ceramic coating available for an additional fee
 
Please read the details below to ensure this is the correct purchase for you:
-Primary tubes are 1 5/8"-Collector is 3" wide
-Exhaust flange is cut to accept a 2 1/4" or 2 1/2" exhaust.
-Adapter is needed to fit other sizes.
-These headers will only fit small block Oldsmobiles with 330, 350, & 403 engines from 1965 to 1976. 
 
This excludes 1965-1970 B and C's because the steering boxes are rear mounted (towards the fire wall) and all other Oldsmobiles with rear mounted steering.
The Toronados will also have clearence issues. If you can fit factory exhaust manifolds, then these headers will fit without any modifications. While they can fit 1965 Cutlass 442 they are a very tight fit.
 
Will not fit Omega
 
Our headers fit a factory 4 speed manual transmission with clearence to the Z bar. They also mate up to a standard exhaust head pipe measuring 2 1/4" or 2 1/2".
They will easily connect to down pipes for a small block Oldsmobile. 
These will also fit in F-body Trans Ams that have a 403 engine.
 
Ceramic coating is available as special order.  Returns on special order items will be considered at our descretion and may incur a 20% restocking fee.  All shipping charges are buyers responsibility.
 
Contact us with any questions!
Sold as a pair, with gaskets.