301 Redirect or Content with Links on purchased Domain

Hi guys, just wanted some advice.

I have a site which is a legitimate business site (not adsense, PPD etc....)

I've just bought another domain which is the same niche (main KW in URL) which which has a DA29 and PA41 (moz), URL Rank 44 Domain rank 34 (ahrefs) and around 3.3K backlinks including one .gov (which are all higher metrics than my main site)

To benefit my main site the most, would you just do a 301 redirect to it, or put some basic content on the site and then link back to it? (a glorified buffer)

Thanks in advance!

301 works. Try it

My only reservation with a 301 is the links look like they're a little spammy i.e. completely off topic etc... and I can't afford to tank my main site.