i bought a 87 s10 t5 not sure what the ratio is yet. it is being shipped in. most of the charts iv'e seen only go up to an 85. i am keeping the 235 in the 54 3100 and just want to drive 16 miles on the highway to work. i have several rearends i am looking at. one i think out of a 55 that will bolt up. the owner thinks it is 410, checking on that. i have one avalible out of a 69 chevy truck. some modification required from what i read. owner thinks it is 308. i hopeing for 373. i have read lots of post on here on this and just hope i am on the right track? any advice would be appreciated.