engine rebuild estimate
 

About how much does it cost to rebuild an engine not including major parts like pistons and stuff, just the necessites and the labor.

depends on what needs rebuilt? if u already have pistons and rings to go into it and just need everything put back in and are able to use ur current connecting rods and crankshaft and dont need anything done to the valve train, then ur just gonna have to have a new head gasket put on, new fluids replaced, cylinders checked, if need be rehoned and deglazed, probably just 400-500 bucks to open it all up and figure out what u need if need be u can be looking at 1000's if alot is needed, just depends on the condition of ur engine, and engine components. sometimes its cheaper to just get a new engine block all together.

A typical engine rebuld includes pistons, rings, bearings, seals/gaskets, and a lower end balancing [I never do an engine without that step]. All that work usually runs around $1200-1700 for parts and machine work, and that's all it would cost if you assemble it yourself.

Here's a breakdown on mine when I rebuilt it:
120 for main bearings
80 for rod bearings
60 bucks for the bottom end gasket kit
10 bucks for the rear main seal which didn't come with my kit
100 for the rings
100 for a new head gasket
15 for an intake manifold gasket
30 for an exhaust manifold gasket
80 for a new timing belt
30 for new PS and Alternator belts
30 for plugs
50 to replace worn out hoses and fittings
3 for a new pcv valve
3 for plastigage
5 for an oil filter
5 for a fuel filter
10 for coolant
30 for oil
30 for transmission fluid
50 bucks for a couple of hardware kits (nuts and bolts/cotter pins/crush washers/o-rings)
300 for the actual bore/balance which was cheap and the work reflected it. The engine came out last weekend after 3000 miles because of loose pistons and a warped crankshaft.

Unless you've got a full shop of tools, I'd factor in 200 bucks to buy special tools and assorted hardware you'll find that you need.
You should also seriously consider a new oil pump (100), water pump (50) and distributor cap (15). These are all prices for my vehicle so obviously your prices might be significantly more or less.

is it wise to use the stock crankshaft, what exactly is balancing? How much hp can stock gsr rods handle?

yes stock crankshafts are very strong and very reliable, i have yet to hear of one breaking, more likey u bend a rod or burn a valve first , balancing is important in making sure everythign spins evenly when the crankshaft is rotating and the pistons are going up and down, if u dont balance the engine properly stuff will begin warping and breaking once higher rpms are reached, and things begin blowing out, like ur crankshaft seal.
no idea about the gsr rod question

what about overboring the block, whats a good overbore size .025" or .040", whats the limit? and price to sleeve a block? does that have anything to do with overboring?

you can overbore the cylinders to increase displacement, but in doing so u will now definitely need new pistons and rings, to fit the new sized bore.