Are you having an issue with it hitting 205 or is it that when it gets hot enough to stall it happens to be at ~205? as 205 ain't terrible. Are you running gasahol (10% ethanol alcohol) which can act up at 205. plus alot of temp gauges are not dead on accurate. I would toss the restrictor & use a 180/185 stat & if the real problem is the stalling then we can attack that. More info please. & does it get to 205 & shut down or does it get ever cooler on the highway OR around town?