How many miles? Talking in terms of years is meaningless if you put a 100 miles a year on the car (not saying you do/don't). I know many cars on this site are not daily drivers.

 

Age has a lot to do with it as well..Especially anything with rubber in it..

 

Rubber that has seen a lot of heat time (headers next to the mount) and heat cycles will be in much different shape than a part that has been sitting nice and cool in a garage. I've bought plenty of NOS rubber parts that were perfect, even after sitting on a shelf for 40 years.

 

My engine has been bored to 40000 , originally a 2 barrel carb ( 289) now has a 4 barrel holley 600 carb ,heddman long headers ,etc. Nothing crazy but it will have some pep compared to before , I decided to buy the lakewood motor mounts since a found a great deal on amazon.com w/ free shipping.By the way , my car is almost a daily driver , since i drive it at least 3-4 times a week.Any suggestions???