You might well be able to bore it to 4.13" and have it live, but you will lose more in ring seal than you will gain with the cubic inches. Anything below .100" is going to cause cylinder bore distortion under load on a standard FE block, and you will lose ring seal and power as a result.
If you want to increase the cubes, a stroker kit is a lot friendler than boring the heck out of your 390 block...
Jay Brown
1968 Shelby GT 500 Convertible, 492" 667 HP FE
1969 R code Mach 1, 490" supercharged FE, 9.35 @ 151.20, 2007 Drag Week Runner Up, Power Adder Big Block
2005 Ford GT, 2006 Drag Week Winner, 12.0 Daily Driver
1969 Ford Galaxie XL, 460 (Ho Hum....)
1964 Ford Galaxie 500, 510" SOHC
