I'm putting an olds 455 into a 78 cutlass and I'm looking for some headers that would fit, any recommendations?

 

I found these.

https://www.summitracing.com/parts/a...utlass-supreme


I'm not 100% on these. They say big block, but if you scroll down they list the 403 in the fitment. You might wat to see if you can contact American Racing headers and see what they say on a part number.

 

I see they still haven't taught up on production with a 3 month lead time. Unfortunately, they're the only game in town, unless you can find a nice used set.