Just my opinion - if you are abusing the car enough to require frame ties, then you may not be that concerned about hurting the value of the car. Also IMHO, bolt on ties are lip stick on a pig - looks nice, useless for the intended purpose.
1967 Falcon 4 door 351C-4V
1970 Mustang 351C-2V
http://raceabilene.com/kelly/hotrod
Owner built, owner abused.