First off; the 4L60 was not produced until 1992. So if your trans is in fact out of a 1987, then it's a 700R4. Granted the internals are IDENTICAL.

The easiest way to tell the differce is to look at the casing and the tail shaft bolts.

4L60 - 3 case halves and 6 bolts on the tailshaft housing.
700R4 - Single case half and 4 tailshaft housing bolts.

Now if you do infact have a 4L60 then you must know that there are two variants. The 4L60 and the 4L60E... simple to dicern which is electronically controlled. The other will have a kick-down cable.

And yes on both the 4L60 and 700R4 you need this cable otherwise you will always be in OD and the trans will not downshift properly. If it is too tight the opposite will happen; you won't upshift properly and will never engage OD.

As far as your question goes for which flexplate you need... Take off your flywheel and drag it to a local parts house that keeps flex plates in stock. Call first of course, but ask if they have a flexplate for a 82-92 Chevy Camaro with an automatic. EVERY single one of them came with the 700R4. So you can compare and contrast. Post up pics and I might be able to get a steel adapter made if the hassle isn't too much.

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