i have a 1971 402 bbc with block #3969854,also have a moroso 8qt.oil pan that works with up 4.25" stroke.my goal is tochange it to4 bolt billet main caps,forged 10.5:1 cr,with 4.25"(or4.")stroke steel crank(6.135 rods),using crower (all roller) cam setup (a voodoo cam with 629"lift and 261 dur.),lifters,and rockers.the heads and intake are totally dressed up closed chambered ovals (#3917215)with an older torker 2 for oval topped off with a reworked mechanical sec. 850cfm carb. msd will get the firing started for a 1600 lb. street legal street-altered. the question is of displacement, i want at least 427 cid (knowing that is possible) would being closer to square on bore and stroke be better also?i would appreciate any professional engine builder's feedback,thanx