i have 62 diesel in my 83 caprice, its orginally equpped with diesel but the size of the engine in been cahnged during the years...

now im been thinking some gears... i have good memory in my mind about my 6,2 blazer mpg when changing 3.08 gears to 4.56 ones... maybe some 6-7 mpg change in consuption...

now wondering if i can do the same for my caprice...

i have od trans so the 4th gear is 0.70 ratio... but what could be the caprice orginal rear gear ratio.. where to find it...

correct me if im wrong but some 1800 rpm would be what 6.2 likes... now i dont have that much... gear calculator says that at 1800rpm@55mph needs some 4:1 gears...?? does anybody have some experience about the issue...