I have a good condition B23E here with 405 head and K cam, ie: the configuration that Volvo rated at 136hp, with around 260-270,000km on it from memory, it came from a car I used to drive regularly, and made good power.
All the bolt on parts from a '77 are a direct fit, including the carby manifold, as others have said you'll just need to plug the injector holes in the head, easily done with some small welch plugs.
I'm happy to sell it for $120, the only catch is I'm in Victoria. I can put it on a pallet and take it to my work, where it could be picked up by a courier if you make the arrangements.
Pics:
Send me a PM if interested.