Compression vs boost question

ok so when you said i should get a temp engine for it i went on craigslist an started searching! i found a 318 rebuilt by keith hershberger in woodburn (hershberger motors) with mopar purple cam 284/484 and .030 over forged pistons. less than 1000 miles, but he sold the swirl port heads off it :/ oh well im stickin my 340 heads on it and he's taking 300 for it! now i'll take my time building the tt 360 set up thanks for the advice~