If you do not have power steering, an aftermarket may fit. I have power steering on my 63 4000 and am having to do major modification of the lower neck to clear the power steering belt.
If I had it to do over again, I would have bought on from Abingdon Equipment. They have it in stock and it is only a little more than the one I bought.
The tanks are not as nice on the aftermarket one that I purchased. It was made in China and the workmanship is just not as good.
Good Luck,
Tim