Front springs ?
I have a pair of front springs that were givin to me 20+ years ago. The owner said they were F40 (65) or F41(66). There are no tags ,stickers or paint globs on them ,they are short and made of heavy wire .They were removed from a custom 66 Small block . 
My question is how can I tell the difference between a standard 65 BB spring ,a F40 65 spring or a F41 66 spring .? Someone told me the 65 F40 and 66 F41 are the same .....Bill
My question is how can I tell the difference between a standard 65 BB spring ,a F40 65 spring or a F41 66 spring .? Someone told me the 65 F40 and 66 F41 are the same .....Bill