rebuild overhaul 4AGZE

[Ivan141]

That's a lot of questions.

Gasket sets can be bought much cheaper aftermarket, anything but the head gasket is not that much better @ Toyota I would expect.

If you haven't spun a bearing, chances are you can get away with regular sized ones. Cranks don't wear down if the bearings do their work, you can usually only fit undersized bearings after having the crank ground down.

ARP studs: only if you cant get cheaper ones. These parts become critical when aiming for high rpm's, which is pointless on a GZE.

Head gaskets: Toyota makes good quality ones, so staying OEM there is not unwise. I wouldn't bump compression on a supercharged engine without knock sensors. Either boost it harder with a turbo or bigger SC, or keep boost more modest and go with more compression. High compression and high boost can be a dangerous combination without some safeguards (like knock sensors, and an ecu that will know to pull some timing when it detects knock).

OBX does nice headers for the lowest budget. Quality is okay from what I've heard (from Robokill), minor design flaw on a pipe transition without a step, but that's easily fixed. They also make a more expensive (470 dollar) high-rise header, but I'd guess it is a bit overkill for an unnaturally aspirated engine ;-) (and it comes awkwardly close to the distributor).

That was my 2p (half of which is admittedly 50% 'knowledge' I scoured from the internet over the past 10 years).