That depends , One you have to see what ratio rear you have now , (tag on rear cover should tell you) if it is howling you may have lost oil and burned up the gears , look for oil leak , last you my just have a bad pinnon bearing going bad , most stock 4 speed early 2.0,s had a 3.55 or 3.40 , later 3.18 . if you swap in a 8" rear you my be lucky to find a 3.55 or 3.40 gear , but you will almost pick up almost 75 to 100lbs in weight , next is do you just stay around town or on the hwy , low gears get up and go and engine screaming on hwy , high ratio gear good gas milage and quite on hwy , standard rear ends were lower gears , auto I have found 3.4 up to 3.00 to one , had one that was 2.79 in a MPG pinto and was a slug , but good MPG ,