The Mercedes radiator should be fine if it is a replacement aluminum core. If it is a copper core, replace it because it will not cool if your engine is modified.

Make sure the pusher electric fan is working, and you should have no problem.'

If the link rod is too short, make a new extension for it from steel dowel, bend it to the shape you need. You heat the end cherry-hot and bend it 90* to fit in the bushing, then trim it to length and use a tubing cutter to make the groove where the circlip goes. Just thread the end into the original linkage end and adjust as necessary.