Ask Mike Sobotka about old tires... I drove his 72 Stage 1 ragtop to Oregon on 'new looking' 5+ year old BFG's. 3 hours in, 1 blew out. 8 hours in, another blew out. Same thing on the drive home... ALL of the 'new looking' 5+ year old BFG's blew out on me while I was driving...NOT FUN. I also enjoyed a high speed blow out at 75 mph... Yes, I needed to change my draws. Like everyone has said, your life and the lives of others is NOT worth the risk!!
Maybe I ought to replace the original Pirelli ZR rated tires on my 05 GT soon. o No: :Brow: I did have it up to somewhere north of 75 mph recently with no issues.