Engine swap question 454 into my '83

[nikwho]

I have an '83 K10 with a 305 that I want to replace. I bought a 454 out of an '82 Blazer. I got some big block heddman headers with it too. I have a manual transmission so i'm pretty sure that my flywheel will bolt right up to the big block(i'll probably replace the flywheel since i'll have it apart). So, I have the headers ready to tie into the existing exhaust system and flywheel shouldn't be a problem. My concerns are with the engine mounts and fuel pump. Will I have any issues here? Will I need to run an electric fuel pump? OR a lower profile manual fuel pump? Will the big block bolt right up where the small block was? Do I need different frame mounts for the engine or anything?