360 Block for 408

i just have the one
its a 74 360 that came out of a motorhome (i believe i paid 300 for it, with the 727 transmission)
i didnt buy it intending to build a 408 out of it, simply to replace the worn out slant 6 in my duster

when i got it home i cleaned it up, had the heads freshened up, put in a different cam and a 4 barrel intake and called it good
about 1000 miles later i spun a rod bearing

thats when i dropped it off at MRL to have him rebuild it is as 408
nothing too wild, she makes 420 HP and 470 footpounds of torque

only thing i would change is the flat tappet to a roller cam so i dont need to worry about zinc content in the oil
but thats not that big a deal, wallmart carries STP zinc adder for 3 bucks a bottle or so