Lawd, I hope those numbers will pull your 5,500 lbs.! A stock C20 350/TH400 would've handled it fine.
Not a car, but it weighs 6,500 lbs. and pulls like a skyscraper:
This load weighed over 9K... towed it 500 mi. with no trailer brakes:
3/4 ton 2WD International:
Others that I don't have pics of include:
FIL's 1500HD (40 miles on his 18' car trailer - 7,500 lb. total?)
'73 K10 on a heavy 18' equipment trailer - 100 miles, somewhere over 8,000 lb.?
'03 Beetle TDI on that same trailer - 40 miles, around 6,500 lb.
'68 427 Corvette on dad's 16 ft. car trailer - 100 mi., 5,500 lb.