The short answer is I am using a KN needle with red springs. It was recommended by a person who had a wide band AF meter and similar mods as my engine, which are an increase in CR to about 9.5, 150 hp PI cam, and the dual outlet exhaust from a later TR6. He found that the lighter (4.5 oz) red springs gave better acceleration. He also gave me a modified profile for this needle for better performance-it is .001"-.002" thinner starting at station 2.
Berry