i've driven a r31 gts-x with the nics red top and there was nothing there to make me smile in my eyes my rb30e goes harder, from memory the nics red top was only 20hp more than the l20et, to its defence though it was the very next 6cyl engine nissan produced after the l20et, silver top has 205hp at the fly same as the intercooled fj20, produces around 15 more Nm at 6500rpm and with around $2500 in mods should produce around 160rwkws, rb25 turbo and remap 180-200wrkw, vg30 turbo and remap of stock ECU 200-220rwkw...parts and upgrades are at your fingertips from a range of places!! my two cents...