what size of USSR,USA,Warsaw Pact,China,and NATO armys during the 1980s?
i need this info for a cold war scenario.

When in the 1980s?

I suggest your best route for this info (if it's for a private scenario) would be to grab one of the paper boardgames of the period and see what they used as OoB.

If you need primary sources it's a bit more problematic. I can't remember if Soviet Military Power had OoBs or not, and it's a bit on the biased side anyway.

What unit level are you going down to? Corps/Divisions?

the ealys 80s Corps will be good.

I've got a book somewhere about the balance of power between Nato and the WP, it mostly details total numbers of things such as troops. tanks etc though, would that be useful? It was published in 1981, so it would be about then the stats are for...

Orbat.com has a decent history section containing NATO and Warsaw Pact orbats at their highest point; i.e., before the 1988-89 force reductions. Also specific studies of US Air Force of the time is useful from there.

I've got some others - numbers, corps, divisions, amount of equipment - in some old journals from 1983-84 entitled 'War in Peace'. Jolly smashing resource, by the by. I'll dig them out.

I would look at a Janes for the info. They usually have a few pages showing some general size and composistion statistics. For details though you will need a different book or each platform of a specific year, ie Fighting Ships, Fighting Planes, etc.

Aside from the excelent orbat.com articles, 'The Military Balance' for the relevant years should be extreamly useful for you - it's well regarded and has totals for types of equipment and outlines of the various nations armed forces.

While the above sources for raw numbers will prove very useful, I would counsel caution against simply 'counting bayonets'. This has proven to be a poor indicator of combat worth.

That's why my first choice would be to see how people have translated raw data in effective combat strength and use that too. You either need to have a lot of unique units to capture the varying capabilities or artificially increase or decrease the unit strengths of the various potential combatants (which leads to problems in itself).