Ok, this is gonna sound nubbish and foolish. I tried using DW20 for 1.7.10 and it crashed repeatedly on initial worldload using java 7 update 71 and java 8 update 25 and java 7 update 71 again for good measure. i uninstalled and reinstalled ftb to make sure it was current version as that was listed as a problem. i checked ram and made sure it was set to 3Gb. i removed java argument -XX:MaxPermSize=128M to see if that would help and it did not. I manually added forge for minecraft 1.7.10 in the mods folder and removed it when that didn't work. My next post will include my log file, hopefully in a spoiler tag.