Yes I would also go S/C or juice to make a honest 400 streetable combo, it can be done naturally but hard streetability. back in mid 80's before aftermarket heads, we had a Maverick 289, 12-1's, 620 lift crane flat tappet, twisted torker, 750 DP, 351 Windsor hds early style w/ 194 155 valves, DougNash proshifted trans, 5:13's, tractrion bars and slicks it went 11:30's in 1/4 naturally aspirated. We did street race this car but would not have been a daily driver what so ever.