454 engines are very easy to come by. If I were looking for 1 i would just check the newspaper for a mid 70's 1 ton truck. these trucks can usually be bought for around 5-800 dollars and if you are lucky it will come with a short tailshaft Turbo 400 trans as well. You can yank the motor and trans and mabey resell the truck for 2 or 300 bucks and then your only out a few hundred for your motor and trans.
I hope this helps,
Ditto on the older P/U's b/c mine is a C/K-20/30 '74/'75 motor!!
It was just a good core with a bad crank, but had the good -781 large oval port, open chambered heads on it. Gave $300 for it back in '95...
I was going to make a 475 incher but the dreaded "more power, Scotty" bug bit me so about all I used to make my 496 was just the good block and the good truck rods!!!