In general, one should be taking one's distributions based not just on one's current tax bracket, but also on what one thinks one's future tax bracket will be. For instance, if someone is currently in the 22% tax bracket, but thinks they'll be in the 12% bracket later, they should not take any distributions now.
In your case, if I understand the formula correctly, you'll have an RMD of around 74k, bumping your income up to 164k (assuming the 90k pension is life-long) for your first year, which is just barely into the 32% bracket. This means, assuming tax brackets stay the same (24% being $85,526 to $163,300), you should bring your distributions up to $163,300. With one additional dollar, you're choosing between paying 32% now or 32% later, so it doesn't matter (if we ignore all the further complications). However, at some point, if you take enough distributions now, your RMD will be low enough that you won't have any income above the $163,300 later.
Another complication is gains in your account. If your account doubles, your RMD will be 148k, making your total income 238k, putting 31k of your income in the 35% bracket. In that case, you'll want to take enough distribution now that your future RMD doesn't put any of your income in the 35% bracket. That is, you may want to take some income now in the 32% bracket to save yourself taking it in the 35% bracket later. How much depends on what you anticipate your account doing.
And then of course there's also the tax brackets themselves. One way for accounting for them is to assume that they'll increase with inflation; it that case, when you look at your expected returns for your account, you should take what you expect the real returns to be to calculate how much you expect to have at 70.
Yet another issue is your filing status. You didn't mention a spouse, so I've been assuming you're filing single. If you're married, or you get married later, that's a further complication.
And as Aganju says, you should look into have the money go into a Roth account.