I have a 240z that I have drag raced for three years with a 75 modified 280 engine that ran flawlessly until a missed speed shift at over 8000 rpm left me with a wonderful two piece crankshaft(aarrgghhh).Anyway after amazingly making it home 40 miles, with believe it or not perfect oil pressure, I put my old 240z block back in the car but retained my .070 shaved, ported and polished N42 head.This combo has given me a compression ratio of approx 10.6 and runs with 36 degrees total ignition advance.THE new combo runs perfect and I have since drag raced the new combo with a best 1/8 mi time of 8.88 @ 79 mph(the old 280 block ran a best of 8.56 @ 81.2mph(( 1/4 mile time of 13.4 @101 mph)) but that was speed shifting at 8000 rpm which I obviously no longer recommend:: LIFT THEN SHIFT :: THE CRANK YOU SAVE MAY BE YOUR OWN: I am now slower than I used to be,which is NOT GOOD. SSSOOOOO what I am now contemplating is an 82 280 block w flat top pistons and the aforementioned head which will yield an 11.8:1 ratio. Now I know everybody says dont go over 10:1 compression on a street engine but my 240z block runs great at 10.6 on 93 octane.I know the longer rods of the 240 make it less likely to detonate but i am thinking of putting a 282/292 duration cam(it has a 272/282 cam now)with the 280 block which I THINK MIGHT ALLOW me to get away with this high compression. I know Hot Rod magazine built an 11:1 chevy this year and it ran on 87 octane with longer than normal rods BUT THEY DID USE 87 OCTANE pump gas!!! NOW AT LAST MY QUESTION. I KNOW WHAT THE DATSUN HOT ROD BOOK SAYS, BUT I WANT TO KNOW HAS ANYONE OUT THERE IN Z LAND PERSONALLY TRIED THIS COMBO WITH DISASTEROUS RESULTS??? P.S. fuel system is modified SUs and electronic ignition off 78 datsun 810.