[sybir]

Cast-iron block, old-school motor.

4G63's hail from the glory days of inaccurate engine management, crappy gas, and less educated consumers. I'm not saying that as a bad thing. These are motors more akin to 1J/2JZ's, RB25/26's, hell, even the old EJ22T's (which were closed-deck and had forged internals, on a motor that only made 6 pounds of boost stock). They're built to take abuse, which means with proper management you can make serious power on stock bottom ends. Iron blocks that take heat without deforming and flexing, forged internals, etc. A motor that has to be able to handle bad gas and hamfisted driving and a management solution that has orders of magnitude less resolution than modern cars means they're overengineered in a big way. Same reason 1G DSM blocks are stronger then 2G blocks. Overbuilding costs money, adds weight, etc, so when you're able to engineer solutions to a more refined endpoint, you have tighter tolerances and don't overbuild.

The new Evo is a completely new motor, with an all-alloy block; and you're not seeing numbers like the old cars for a reason. Even with all the engineering int he new GTR, you're not seeing 1200hp street-drivable cars like you saw with R32-R34's with RB26's. There's a reason many JGTC Toyotas still run 3SGTE's (GT4/MR2 Turbo motor), same idea - old school iron block that can take abuse, and has a much higher performance envelope when you can take advantage of it.