So I got 3 NOS GE 12AX7WA's for a VERY good price. Unfortunately, I need 4 for my Allen Old Flame. It has Tung Sol reissues in there right now and it sounds great. The tube topology is: V1 - first and second gain stage, V2 - reverb driver, V3 - reverb recovery and gain stage, V4 - PI. So the question is: which 3 spots should get a GE and which one keeps the Tung Sol?