i just had a 3.08 limited slip centre ,and gears, fitted to my diff,, feels ok,,,,the old setup was 2.73 open diff,,(junk)
its a 26 spline 7.5 inch setup, from 1982
will 3.42 gears fit this 3.08 possi,,,as all my parts are bought from america,, i cant afford to make a mistake ordering parts,,,,,,i am 12,000miles,,away,getting ready for drag racin,, soon as i get an exhaust ,,,,AND will my first gear be too low,,,,,,with 3.42,s,,with a ,,T700R4,,,as it is a 3.08,, rearend and the low 1st gear of the t700 gives me a 1st gear combined rearend ratio of 3.7;1 in first,gear,,will the gears fit,,,,,will it be toooooo low,,,,in 1st,,,its a good 409sbc,, vortecs, 750 vac 1.52rollers,,vette servo,etc,,

 

3:08 and lower numericaly is 2 series 3:23 and higher is 3 series. there are gears made to fit in either series carrier in any ratio.