Parts are plentiful, the engine is near bulletproof. I had the 1200cc version in a 1971 Datsun B110 when I first got married. I abused, stompped and tortured that motor like a redheaded stepchild for four years.
When I decided to rebuild it in 1976 the mechanic was suprised to find it only NEEDED rings, because everything else was still fine. I put all new pistons, cam and such in it and ran it for years more. It was rated 69 hp and ran like a banshee. I could rebuild the little two bbl progressive carb in the dark.
Did I mention I loved that engine? Told my wife it would make a great TM engine and even mounted a 3M Sutorbilt on the AC mounting bracket for testing. At that time I didn't have the experience to develop that idea.
Prochem did.
I'm sure I could drive a 6008 with it very handily. Just kick up the gas, no worse than me driving the Datsun 90 mph for 10 hours on the interstate.
Just keep oil in it. A characteristic of that motor is that it would need up to a quart every 3000 miles when driven like I did.
Sitting under 2g rpm it would last for ever.