Unfortunately, Offenhauser does not have ALL their original patterns; but do have many of them.
Each time in the last few years that I have ordered an Offenhauser manifold, I have waited 3 to 6 months; BUT each time the wait was worth the product, especially when you compare the product to many of the other products available.
In 40 years of working on and selling aftermarket units, I have yet to have to do any modifications to an Offenhauser unit to make it fit!
Jon.
