White Smoke Coming Out Of Sidepipe

[Mongoose930]

While I was driving home last night, I noticed white smoke coming out of my side pipe. I was a few miles from home and all of temperature readings and pressures looked good so I drove it the rest of the way home. Lots of white smoke under engine load and much less at idle or moderate load. I am suspecting a blown headgasket but I don't have a lot of experience with these engines and was wondering what else would cause this condition and what type of checklist I should go through to determine that it is indeed a blown headgasket. Assuming it is, I should probably plan on changing both gaskets while I am that deep into the engine? Any suggetions on head gaskets? I am leaning towards Cometic as I have had good luck with their products in the past. I am having a hard time choosing a gasket. The 428 bore is 4.132. I don't know if or how much my engine has been overbored but I am assuming .030 over. The bore options on the Cometic site are 4.08, 4.165, 4.25, 4.3 & 4.4. Which one should I choose? Also, there are many thickness options with .040" seeming to be the standard. I know I will need a new intake manifold gasket set which I already have. Should I replace the exhaust gaskets while I am at it? Would this be a good time to updgrade the head bolts to ARP or something similar? Obviously I will need new oil since the drivers side sidepipe had a nice concoction of anti-freeze and oil in it. Am I missing anything else other than a competent mechanic to help me out?