I only have them on the front as of yet. I'll agree with the reviews above. 512's are great You'll love em. I'm not sure what the eye to eye length is on the stock rear 450 shock. I'll try to find out for you tomorrow. The eye to eye length on the rear 512's is 15.5". Oh I just saw you have an 04 I don't know if they are the same as a 2000?