1 7/8 Header Selection
The 5303 are adjustable headers as I recall.
I have had nothing but trouble with that design
on street cars with them leaking at the joints and
the noise made me crazy!
As I recall, the 5304 are a copy of the 1 3/4 race car header
that were built on the same jig as the race headers without
the slip joints and a collector for a street application. I had a
involvement back it those days with Hooker in their California days
many years ago. The tube length worked pretty without additional
length installed unless the car was very heavy.
Jost my .02 = For Free!