100% wet-flow tested and street calibrated All-metal parts(no plastic stuff) New unique shiny / chromate dip finish Universal calibration (1964 & earlier) Manual choke Side hung float bowls Power valve blow-out protection Vacuum secondaries Question:What size is the vacuum line? so I can order hose and fittings accordingly Answer:they are 1/4" and 3/8". the 1/4" goes to the automatic advance on your distributor and the 3/8" is for your power brakes Question:Will this fit single plane intake manifold 5.3 carburated set up ? Answer:It will fit any intake manifold with a Holley square flange know as the 4150 flange. Bolt pattern 5 5/8 x 5 1/8. Question:Will it fit a1983 305 Pontiac grand prix motor? Answer:If it does not fits directly, simply get you an adapter for Mr. Gasket or any number of retailers. The 600 Holley will wake up the 305 Pontiac. Question:wil it fit a 350 chevy Answer:It will fit a 350 Chevy as long as the intake manifold has a square bore Holley bolt pattern for the carburetor (5 5/8" x 5 1/8"). If the 350 engine still has an intake manifold for the factory Quadrajet carburetor you will need an adapter plate like the Mr. Gasket 1932. One of the most trusted carburetors of all times -the 1850! Its 600 CFM of airflow, vacuum secondaries, single fuel inlet and mechanical choke makes it amazingly universal. The 1850C has a Gold Dichromate finish for corrosion protection and classic Holley looks.