did a 1968 ss 396 have a vented or non-vented radiator cap? if it was non-vented,am i better off custom fitting a resovior type system,or will a "catch can " and non-vented cap work fine. i have an aluminun radiator from summit racing and an aftermarket shroud from ground up restorations. also a 17" clutch fan. thanks for any feed back!!t.s.p.s. i'm trying to "mimic a stock look"

did a 1968 ss 396 have a vented or non-vented radiator cap? if it was non-vented,am i better off custom fitting a resovior type system,or will a "catch can " and non-vented cap work fine. i have an aluminun radiator from summit racing and an aftermarket shroud from ground up restorations. also a 17" clutch fan. thanks for any feed back!!t.s.p.s. i'm trying to "mimic a stock look"

Think you got gas caps and radiator caps mixed up. Coolant expands as it heats up and thus pressure builds up until relieved. The radiator cap has a relief valve or "vent'. Question is does the vented air and or coolant flow onto the street or into a reservoir? Yes reservoir is a good idea and can be retrofitted if need be. Later model radiator caps have two-way valves provison, so the coolant can be "sucked" back into the radiator as the coolant cools and pressure goes below ~14.7 psi ambient.

My $0.02

thank -you for the info, guess i'll put a catch can in. tom.

Ditto on the mixup and ditton on the recommendation. What a "catch can" does is provide a means to eliminate air from the cooling system. This in turn not only improves cooling efficiency but makes coolant last longer too. All good things which is why ALL modern cars have this design feature.