318 with 360-587 1.88 heads

i wouldnt worry about the push rod length. Figure the cheap head gaskets are .045 thick, funny how when schmos change head gaskets no body crys about too short a push rod...
'a lil' extra pre load wont hold the valve open. milling is around 60 bucks, u might have 120 bucks tied uo in it meanwhile the rhs heads have too large chambers and would need work as well and new rebuild heads cost 400 plus.
id at least mill the 587 to get an honest 8.5....otherwise itll be gutless down low with **** for snap.
thats why people always cry about 360 heads sucking on a 38teen....cause they eont mill them to get better than the 7.5 compression they end up with...