There is a difference between carbed and injected rotors.I think it is the thickness,(it was pointed out to me years ago but I forgot)neither are vented.For what it's worth here's how I've set up my brakes on 3 different 140's.Go with 164 vented front rotors and calipers.They are a direct bolt on.You will also want to change the front wheel studs.164 studs are longer.you can bolt a wheel on with the 140 studs but it's dicey.When I got into volvos 15 years ago rear calipers were plentiful but it seems they are drying up.Use 240 rear calipers with your stock 140 rotors.You will need to change the brakeline fitting at the caliper end and drill the caliper mounting holes very slightly larger.The offset is correct and the pad contact patch will remain the same.Brake pads will be available everywhere! When I first did my swap on my most recent car they didn't stop as well as the other cars I did.I had bolted on all the parts used (pads were like new so I went with them)I bought new rotors and (metal master) pads and it was a day and night difference.Don't skimp get new rotors and decent pads! (and I'm NOT running a brake booster!) With boosted brakes and the parts I listed you'll be amazed.I think the metal masters make a huge difference but people will tell you you'll have a hard pedal etc.I think they're nuts.Even my adorable wife can operate those non boosted brakes just fine so double check the hand shake on people bashing them!