Plz Help With Suspension Local Would Be Great Philly PA area

[maxtegroom]

i have a c70 in amazing shape however over the last year or so i has developed a shake or vibration at speeds above 50mph throughout the whole car i have tried rotating and balancing the tires which are little old but in great shape and no seprated belts.. the tie rods are tight and no visible play in the control arms.. i was wondering if struts could do this they dont seem bad car has 90k on it.. i am also wondering if there is anybody local philly tristate area that would be willing to swap wheels for a test drive just so i could really rule out wheels and tires.. any help is greatly appreciated!1