thought the 88s were electric but i guess i was wrong...... easy.... pull the tail shaft on the new tranny, pull the VSS out, pull the VSS "gear" (not really a gear)...... put the cable output and gear from your tranny in that one...... your set assuming your 88 is a 700r4 which it should be
just did it to my 84 s10 that was converted to 89 tbi
ok, well since you dont have a cable output from your old tranny either go to a junk yard and find one or goto a tranny shop.
To get the mangetic gear off the 90 tranny's output shaft you will need a puller with long arms.
The cable operated gears come right off with a wierd clip.... and the 90 tranny will have the holes for the clip too
whatever you do the cable ones are easy to take off and on... the VSS magnetic gear is a pain to get off w/o a puller
all 700r4s use the same ones..... even for the 2.8's..... i have a cable one from a 2.8 in my 4.3's tranny..... i wouldn't be suprised if other trannies are the same too