thinking of doing this cause i am going to be in my tranny shortly. mainly i want to know if i am driving on the intrstate and go from 4th to 5th will there be a noticeable drop in rpm or will i not notice it. i know it will be better for me in gas mileage when cruisng. also is it the 5th gear that is needed and the final or is the final a ratio or a actual part that will be needed. thanks for you guys input, pro's con's.

also from a very knowledgeable source i was told i need those parts from a 90-91 ls tranny but at the time he said he was not 100% sure. what tranny do i need as a donor tranny? thanks.