While operating my car and before ~192 degrees it seems to run okay. But after the temp. Is reached and when I come to a stop where the engine is closer to idle, approximately 1000 to 2000 RPM's it begins to studder and eventually die. I attempt to accelerate during this episode and it seems there is no fuel getting to the engine unless I hold the accelerator down allowing it to get a bunch of fuel. All of this occurs only when the outside air temperature is above 65 degrees or so. On nice days only. The engine is in a 1967 Camaro and is a 1998 LS1 with much of the EGR system removed, if not all of it. It has headers and stock computer and engine wiring. The manifold and throttle body are also stock. I am not running catalytic converters.I am running O2 sensors on both sides however. I have a manually adjusting temperature electric fan which is not controlled by the ECM. It has the stock 1998 thermostat in it, I believe which is new. I believe the part store gave the right thermostat to me. I am at a loss for answers please help with what you can. Thanks in advance. My make is a 1998 LS1 engine with modified single inlet to engine fuel supply, 75,000 miles on ticker, blocked off EGR port on top and front of intake manifold.