My 87 is a hybrid of sorts. Was a 307/200-c 2.14 rear car before.
You will want to change that trans out too. The 3 speed was built to be light and cheap. I broke mine twice just behind my 307 V8.
There are a lot of things you have to consider when doing a LC2 swap. You will have to change out the fuel system (need a tank, pump, lines, filter, etc). You will need an electric cooliing fan. You will need to get some type of exhaust as well.
My best advice to you, is to get a wrecked/parts car to just have to pull parts off of. If you buy just an engine/trans/rear, you will end up scrounging around for a lot of extra parts.
Good luck! Would make an interesting swap.