I was more active in the Inliners club in the 90's before the Internet became popular. We had to discuss this stuff in person... grin And like today there was the " old school" and "modern" engine discussions, but it was the GMC 302 or Chevy 261 VS the Chevy 250-292...
Not everyone needs or wants a modern looking engine in their vintage car/truck or needs the performance potential..Open the hood and it all looks so simple with an old inline.
On the other hand, if I wanted a powerful 6 cylinder in a more performance oriented vehicle I would consider a more modern engine.

70 Triumph 650 cc ECTA current record holder