I'm looking to buy a used 4 dr truck w high miles which one will be the most reliable and best value?
Go Chevy, the silverado 1500/2500hd have the best ratings and there engines last a long time. as long as the maintenance is kept up.
Avoid Dodge Ram
Toyota T100's are great and they have a low fuel consumption with their v6 powerplant most guys miss those models. They are pretty reliable, then I'd go 99 to 01 Chevy and same years for Ford. I owned a dodge and never had problems with it but if you don't know about dodges you should start with a Toyota or chevy. If you happen to stumble over a dodge make sure it has the 360 or 5.9 litter eng as it has more power than the 318. Also consider getting the 4x4 dodge xcab very reliable and cheap trucks that last a while. check out this comparison test link below with all 4 makes: Happy hunting: http://www.edmunds.com/ford/f-150/2000/comparison-test.html
id personally go for either a Tacoma, or a silverado. i like the 99-02 silverado model, the only downfall is the speedometer and the rust problems on the rocker panels, other than that there good trucks