My setup was pretty much a stock bottom end 6 bolt. I think I mentioned this on instagram, but I can add some more color here. I have run 3 turbo setups on b18-b20s in my wagon.
First was a B18 D, cast +.040" pistons, on a worn out block, stock rods and a C cam running an HL-15g. Had about 5k of hard miles on the setup at 16psi with very minimal porting. Broke the ringlands after upping to 18psi, and polished the cylinders to a mirror shine. No other failures, rods were still straight, crank was fine, bearings were all perfect.
Second was a 73 B20 F, stock bottom end, used (probably 5k miles on pistons and block) +.020" pistons, stock ring gaps, D cam, 350cc/min injectors and megasquirt MSnS single coil, batch injection, and an HL-16t. That setup saw about 8k of hard miles at 18psi. Had a fueling issue at the track, and ran lean under WOT at 6k for a few too many hits, rings butted, polished the cylinders, and cracked a couple ringlands, and broke the m41.
3rd was a 72 block with 73 head, +.030" new pistons, ring gap opened another .005" from stock, K cam, 900cc/min injectors megasquirt 2 with wasted COP ignition, heavily ported head, 16t, shorter header design, better cooling, and huge intercooler, 3" exhaust. That setup saw about 10 miles mostly at 18psi, with a bunch of track/autox/drag days at 22psi. Did well until I ran one really short autox where I literally could not get out of first gear for the entire course, and was on the 7k limiter for way too long. That one died of... wait for it.... you guessed it. Butted rings, broken ringlands, polished cylinders, and a dead valve guide.
New setup in the works, going to run a bit looser on the rings. Forged pistons, Forged B230 rods resized big ends for my 6 bolt crank, and a new turbo/ic/fueling setup. This time I'm planning on 24psi on pump gas, 30 ish on e85.