what manual transmisson and tranfercse should i use  iam not new buti am stuck any help apresiated  

well it all depends on what tuck you have? if you you have a chev id go with the sm 465and the np205, it got granny low which is nice.  

I would go with a 208 unless you are running a BB. it weighs about 110 lbs less and has a much deeper low range too. Service it correctly and use proper axle ratios for tire sizes and you will not have any problems with it. Were people get into trouble is big tires and tall gears which places a LOT of strain on Tcase.  

how much does a 208 weight? i know a 205 weights at least 150-160 so that would put it in the 40 or 50 pound range?  

the 205 weighs 140#.......the 208 is 80#'s  

I would place a 205 heavier than that. I do know that a 208 weighs around 87 lbs and weight was one of the reasons they switched to it in 81. There is a few 205's out there used in GM trucks in 1980 that had a aluminum case and was speced for ATF too  

I looked on a shipping reciept for some I've sent out, without oil. the 203 is 165#'s  

i belive the 205 (with the standard cast case) is about 135! looked it up.