Bad radiator cap?

[suprafanatic]

Oh it isn't huh?

 

[suprafanatic]

A 20 some year old radiator cap with hard and cracked rubber seals would be more likely to be the problem than an HKS metal head gasket and ARP head studs failing. Especially since the car is at stock power.

 

[onemancrew]

What did it end up being?

 

[KicknAsphlt]

I went to autozone to get a new cap but the one they had for my car didn't fit my radiator at all, it was to small.

I ordered a new cap from the dealer one time and it was too small as well -- turns out, the GE and GTE radiators used different caps. Might've been you issue at vatozone as well...?