I'm with George - the 2 liter is a better choice, if not for 500cc more, then for the plain bearings. They're also sensitive to fuel/air ratio and float level and that changes with the weather. Changing the (8!) plugs was no joy, either - an hour plus project!
I love the Vasek Polak quote years ago on 4-cam'ers with their roller bearing cranks: "Once you get used to the Factory Mechanics' style of driving with the rev's always up over 4 grand, the sound of the engine and overall performance is just gorgeous. Just DON'T EVER lug it below 2,000 RPM!"
As a kid, I frequented the shop of Al Alden, who used to build Porsche racing engines for the upper East Coast crowd during the 60's and 70's. He had 1500 4-cam'er holding up one end of his "desk" (just another bench, really). When asked about it, he told about an over-excited (and inexperienced) racer pulling forth out of the pits and lugging it past the slower pit area (thus, destroying the #'s 1 and 4 bearings), then continuing to race until what was left of the bearings welded the crank to the case. He was a doctor, I think, and could afford a new crate engine from the factory - must have been nice.
Al, of course, gained a new leg for his desk.