The 470s are good motors,,but if you do a search on the net you will find that theses motors get a bad rap....they have there problems but once you get the bugs out they are great ...some of the problems are

to small heat exchanger 3" should be 4"

stator charging system w/ water cooled reg. ''' change it out to a reg. alt.

starter take a beatting because of the big pistons... Keep all wireing clean

seals on the water cir. pump and cam ......a must change or oil will get in the oil

And that the bottom end is alm. and the head is cast Don't le the motor overheat or you will blow a head gasket

keep a good abttery in it, and run good cables, if you don't have hte 4" heat exchanger, start looking for one. And regardless of what the sticker on the valve cover says, set the timing at 4 degress btdc. If you can find a Rochestor carb(has two idle mixture screws) for your 470, you will like its idle and starting better than the Mercarb you have(one idle mixiture screw)