Hello and thanks for taking time to read this. I'm putting a 1973 455cid Oldsmobile engine in my 1969 Cutlass S Convertible ( replacing the 350cid ). I've decided to use Hedman headers, my question is, for ease of installation do I need to order shorty headers, or can I still use full length?

thanks!

 

Either one, there are advantages and disadvantages to both. Long tubes provide a larger performance advantage.

 

Thanks OldCutlass, so either will fit?

 

Properly designed full length headers will be tuned to actually improve volumetric efficiency through the careful selection of tube diameter and length for a given engine size and application. The result is long tubes that are difficult to fit due to interferences with other parts of the car. Shorty headers are a compromise that provide none of this flow tuning but do provide a small improvement over stock manifolds. Obviously the shorty headers fit much more easily.

Your call on whether the performance of full length headers is worth the hassle to you. For my money, the shorty headers don't provide enough of an improvement over manifolds to be worth the money. I use full length headers exclusively.

 

Joe-
Thank you for, for this reply, and to the others I have posted regarding my project, I do appreciate your sharing your knowledge.

Dave

 

I don't think there are any shorty headers for big block A body.