from your sig pic i always thought you had one of these i was going to get that one untill i decided to go with the grabber one. 1980's firebird spoilers look good too
These straps have a much larger hook than most(about twice the size of most of these kind of straps),they are rated at 1200lbs each.I would never use just these,I had the front binded down w/a pretty good sized(read-heavy!)log chain.Also,the car had no motor/trans and I only pulled it about 5 miles home on the backroads.
I figured you must have pulled it a short distance. The straps MAY be O.K......it is the S hooks on the ends that will bend and/or break. The straps I use are rated at 5000 pounds each...and I use 4 of them. But.....it I am just pulling it down the road a short distance....I only use two of the straps.
The best straps to get are the ones like we use on flatbeds, 2 inches wide with a solid steel flat hook. I've broke the one inch wide ones just tightning them up. I prefer to use chains and binders to tie down a car, never had any problems with them breaking!
That was a GREAT deal! Most definitely more then $300 in parts there. Awesome score. My grandpa has always used Comealong's to tie cars down for years, and I do the same.