360 block, how thin ?

Hello, new kid on blocks(pun). Bought the "Big Inch SBM" book, by Jim Szillegy? Seems like slick marketing for "buy all new Mopar race parts". I prefer to squeek-by on a production, early block ? Been blowing $'s on sonic testing 5.9L block, .102" thick, non thrust side with std. bore, so .085" ish at clean-up? I suspect too thin. Now I'm looking for 70-74'(thicker) block, to become Hot 408. Bigger heads than"Eddy's", maybe Brodix "MI"s w. 239cc runners, for 59 deg. blocks ? Thanks, Art.:glasses9: