Chaz, just a suggestion. Since the strength of a frame is so important, why don't you do what I always have done, tack it up and have someone who knows how to really weld finish it. I know that isn't what you want to do, but this is one area you can't take chances with.

Maybe you can even find somebody at the local VoTech who will stop by and do it right there at your place. You can slip them a few bucks and watch how they do it (But only if you also wear a mask ). You can have everything preclamped and ground clean, ready for them to just finish welding.

Give this some serious thought, please, as the last thing you want is for your frame to break when you are driving the car. With a little work you can find someone to do this for you. Then you can tackle some less significant parts yourself.

Don