I recently made this swap,using a custom spec comp grind. 243/247 @.050 .570/.575 lift split on a 107° Lsa. I used Howard's solid roller lifters, set them at zero lash, fired up great and ran great. I used trick flow dual springs with 190 lbs on the seat and 400 lbs open at .570 lift. Everythig was working out beautifully untill a carb baseplate screw decided to vibrate out and down into my #8 cylinder !!
It smashed between the piston and deck, lifted the head high enough to let water in and hydrolocked the cylinder.. cracking the #8 cylinder wall..
Please check your baseplate screws guys.. it was something i didn't expect to have bite me.

Engine is currently tore down awaiting a rebuild.😥 ... pulled the cam and lifters out.. everything looked fine.