Transmission noise question

[nail pounder]

I've already done a search but don't see what I'm looking for. I have a stock '58, 235, 3 on the tree, had it a month or 2. Haven't done much driving, mostly cleaning and getting it road worthy. So today my daughter and I spent the day driving it. I'm hearing a loud, high pitched (almost squeeking but not) noise when I floor it in any gear, at any rpm. If I just cruise normally it doesn't happen, it seems like a trans noise. If I just rev the engine it won't do it. I checked fluid level, it's good. I also have clutch chatter in 1st unless I get on the gas but that seems unrelated. Any thoughts? Here's a pic from the grocery store, we had a lot of fun cruising it around today.