Join Date: Oct 2016
Location: Ontario, Canada
The True North concept car actually used RRO parts, according to the RRO website. But that doesn't mean they ONLY used RRO parts. Also, those wheels looked like 16" to me, maybe a 70 series tire. So it's not a huge tire - which makes the wheelwell space above the tire look larger.
Using spacers only would affect the wheel alignment and you'd ruin a set of tires pretty quickly. The 'other parts' are intended to allow the alignment to be restored to normal. I don't know the height of the RRO kit's spacers, but roughly speaking the lift is whatever their height is.
Larger tires lift the vehicle roughly half of what the additional tire height is. Going from 27" tall tires to 29" would lift the vehicle 1 inch. The type of tire and tread depth has some effect, say, going from worn down 27" P-metric all seasons to a 29" LT all terrain, would add tread depth and reduce the sidewall flex due to the greater weight capacity. So the resulting vehicle lift might be 1 3/8".