Now you start spending money if you want the job done properly.
I don't want you think I'm trying to rain on your parade, but you should be aware that a 454 won't just bolt in and you're good to go without any trouble.
You will be tempted to use the gas pedal, of course you will, or why did you buy it?. A well built 350 or 400 or properly built 200r4 will be required, I doubt the transmission behind your tired 305 will last long with 454 torque, and a suitable rear end is another thing to look at.
Upgraded suspension to deal with the extra weight will be another necessity, and brakes as well. Don't forget the cooling system either, a bigger radiator will be another must.
But if you approach the job prepared to do what is necessary and spend what you need to do the job right, you will have an awesome machine indeed!.
Forewarned is forearmed, start looking for what you will need well before you start the job and you should find some good deals.
But a great job never comes cheap.
Good luck, keep us posted with pictures please.
Roger.