1987 chevy block stats? need to know for compatibility

[Thowell]

i am wanting to either buy an extra block or go for the extensive rebuild. and so really i was wanting to know if the four bolt main blocks would work? also the 2.02 heads. i ask because those are the ones that im seeing alot of on craigslist here in kansas city. so just give me your thoughts on how i should go about it. also i was wanting to know whats better. to buy a posi carrier or a locker? i ask because its better to learn before hand than to go pay and have it done and then realize i got suckered. thanks for the advice

[VileZambonie]

4 bolt mains are for heavy duty use and will work fine.

Personally I prefer a lsd over a locker.

[Captkaos]

For a street driven vehicle, 2 bolts are fine and 4 bolts most people overprice

I don't like lockers unless it is on a Jeep for offroad.

[Thowell]

well i mean wouldnt a locker be technically true posi? and should i go buy a new locker or posi carrier or search for someone with a used one?

[Captkaos]

A Posi is what GM called their limited slip differentials.  A locker locks both axles, so no they are different.