Yes you can use your original A/G radiator but if you look at the inlet orientation of the correct LT1 (F-body is perfect) radiator you will note the drivers side inlet is much lower than your G/A body inlet. This keeps your reverse flow LT1 submerged in coolant so not to trap air. It may be hard to visulize but as a test simply pressurize you cap of your G/A body radiator with the LT1 vent hose from rear of head open, you will note you are actualy pushing air from radiator thru head and out vent. Simply cracking T-stat vent will not get this air out.
Before doing my LT1 swap in a G-body , I owned the first Impalla SS in WI back in 93, numerous mods I made back then are suddenly coming back to my memory (50yr old mechanic and gearhead). The LT1 can run the higher than normal comp ratio due to the reverse flow, with any air in system you are risking detonation and engine failure. Using a 1995 F-body application there is a 1/2" vent for the head, this way you dont have to buy the preformed upper hose with its 1/2" nipple and less than idea location (radiator nipple is lower, less air than upper hose).
Hope this helps, everything I read and asked prior did not touch on this important note. Its not so worysome in a stock 260-310 hp application but when you start putting 350+ to rear wheels any air in system can be catastrophic at mid track or summer cruise speeds.
Before doing my LT1 swap in a G-body , I owned the first Impalla SS in WI back in 93, numerous mods I made back then are suddenly coming back to my memory (50yr old mechanic and gearhead). The LT1 can run the higher than normal comp ratio due to the reverse flow, with any air in system you are risking detonation and engine failure. Using a 1995 F-body application there is a 1/2" vent for the head, this way you dont have to buy the preformed upper hose with its 1/2" nipple and less than idea location (radiator nipple is lower, less air than upper hose).
Hope this helps, everything I read and asked prior did not touch on this important note. Its not so worysome in a stock 260-310 hp application but when you start putting 350+ to rear wheels any air in system can be catastrophic at mid track or summer cruise speeds.
