building a big motor takes skill and knowledge they just don't bolt together ,those days are way over . cost 10k -15k if you have nothing .there is more than the motor to think about .like cooling ,fuel system ,ignition, transmission etc .if you have never ran a high strung motor on the street they require alot of maintance , adjusting and great tuning skill .and usally don't have a real long life span .
i would suggest building a 78/90.5 with a solid bottom end and spray it with 50-100 shot of nitrous at the track .way easier to build , less expence and the motor will still make tons of streetable power and run great on the streets and highway and be a animal at the track .
good luck .and start hunting for those parts . great canadian swap meet is a great place to start