most of the stroker kits drop right in anymore without any clearencing of the block. THAT was from 20+yrs ago.

As mark said though, look for a D9TE block as they have a longer cylinder at the bottom and thus support the piston slightly better at BDC.

one of the things to remember is that with flat top pistons you want to stay away from the early heads. On a 4.5" stroke at .030 overbore and flat tops with a 8cc valve relief and D0VE heads your over 14:1 compression. Even with D3VE heads your almost to 12:1.
I would recommend dropping back to a 4.3" stroke for longevity and with a .030 overbore your still at 521cid. Ford motorsports 521cid engine with their heads makes over 600hp and Kaase got over 700hp on pump gas and a mild roller cam with his P51 heads on that engine.