I cbf quoting a few points, so i will just state my opinion on a couple of issues raised and hopefully you know what i am refering to.
1/ At 14psi i honesty do not think you will reach 250rwkw, i think you may require about 18psi.
2/ Suspension plays a big part in drag racing, and if you want a decent 1/4mile time, raise your car (temporarily) to at least std height, this will allow your suspension to have maximum travel. If you have Jap coil-overs then that is a disadvantage, as even on their softest setting they are usally too hard. Remove any strut bracing or roll cage, etc, This will allow the chasis to flex on take off and transfer more weight to the rear wheels.
3/ If you drive like a 40yr old (casual driving style, with the occational squirt, and the rare flogging) then yes, your std motor MAY last 80,000km@250rwkw with std eng, if it hasn't had a hard flogging b4 all these upgrades. But if you like having "fun" and give it heaps every other day, it may only last a week/month/year: Who knows?, just be prepared to build it properly if it decides it's had enough.
4/ MRT, are they the guys that entred Vic. Dutton with a red VY commerdore and a crazy fuel cell set-up in the boot?