until you have driven an early mustang with a mustang II suspension you really don't know what you're talking about that it's better than something that keeps the shock towers in tact. there is a lot of flex going on when you install a mustang II suspension into an early mustang. the mustang II suspension kits on the market are designed for street rod type cars that are just cruisers, they are NOT a performance suspension by ANY stretch of the imagination. and having owned a real mustang II and having driven an early mustang with a mustang II suspension i can tell you that even comparing those 2 there is a big difference, the actual mustang II will outhandle an early mustang with a mustang II conversion and that's just sad.
ya know even Reenmachine isn't doing any more mustang II conversions because for the amount of work needed to intsall it there just isn't much benefit. an early mustang with a mustang II suspension may ride a little better but it won't handle any better than an early mustang with a properly sorted and reworked stock style suspension. install a tcp or GW coilover kit and a rack and pinion and you'll be light years ahead of a mustang II style suspension and probably for less money when it's all said and done.