If it's any help, Clausager says that spring-biased needles were introduced
to home-market HS4 carbs with the 18V engine in 1971. At the same time all
export cars were fitted with HIFs. Other comments lead me to believe that
the HIFs had the same, spring-biased, needle.
(or if that URL doesn't work try )
From: James Nazarian Jr <James.Nazarian@Colorado.EDU>
To: firstname.lastname@example.org <email@example.com>
Date: 04 October 1999 21:40
Subject: Carb needles
>I was looking at leaner needles for my carbs on my 71 and I noticed that
>TPMG had biased and normal needles listed. I just had my carbs rebuilt
>two or three years ago and I don't know which I have; is there a way to
>tell by looking? Also, what is the difference between the two, and which
>might be better living at 6000 feet.
>'71 B roadster
>'74 BGT bastardization with big aluminum heart :)
>'63 Buick 215 cubic inch 'heart'