These fittings fit 1997 to mid 2010 cases. They should be 0.521".
4L80E Transmission Adapter Fitting Front & Rear Port -6AN Flare 6 AN 4l80e Bare
Mr Gasket 9710 Adjustable Fuel Pressure Regulator w/1564 Gauge
Mr. Gasket Gasoline Adjustable Carburetor Fuel Pressure Regulator 1-6 Psi 9710
Mr. Gasket Co. #9710 Fuel Pressure Regulator
Mr. Gasket Fuel Pressure Regulator 9710