New headgasket still overheats under throttle.

I just completed swapping out my third set of headgaskets on my car. It is a 94 cobra with Vortech s/c. It seems to keep burning my coolant passages on the gaskets. The first two time I replaced them with stock Fel-pros this time I went with Mr Gasket ultra seals. I thought I had a cooling issue so I replaced by radiator with a Fluidyne my water pump with a Kool flow from summit, 180 thermostat by Mr Gasket, new hoses, and wired my fan on high with a relay. I test drove the car and it felt great so I got on it a little in third gear and let off after only about 7 lbs of boost however after that I noticed my temperature gauge climb quickly to about 240 (Autmeter mechanical) These seems to be the problem I had before so I no longer think it is a cooling issue. I don't think my car is leaning out I have a walbro 255 intank and a T-rex inline pump I also have 30# injectors with a pro-m mass air meter. I dont hear any pinging or detonation. Could my timing be to advanced? Currently I believe it is at 16 with my boost timing control set at 1 degree per pound. I do not want to damage my gaskets so I will probably stay of the throttle until I get it checked. Could my problem that it need a chip custom tuned? I am running by stock computer but the car has excellent
drivability and idle the only problem seems to be when I get on the throttle. Aslo what temprature should my car reach on my temp. gauge after a 1/4 mile
pass? I would appreciate any advise.