Monetary question...

So for anyone out there, I would like to ask the following:
If you have had your 4.3 engine rebuilt or replaced with a new engine, how much did it cost, specifically if done professionally?
I have three options: Rebuild the exisiting 89 4.3L, rebuild a 93 4.3 Vortec, or buy a new engine to have put in from the dealer...
With any of the new engines, I would definitely like to also up the HP...

why not buy a rebuilt engine? it might be cheaper and could be better

Trust me on this money wise Rebuild the engine in there now the 80's engine you wont be disaponted

I got a grate engine for about $1600(I think),plus $500 to get it put in.The engine had a 18 month ,unlimited mile warranty.

This used to be the cheapest way to go to get the most bang for your buck, I don't know if it still is. Check to see how much for a target motor or short block from GM. You can get them bored .30 or .40 over with the pistons and crank installed. Then have the heads done and the intake boiled out and cleaned. Add a gasket set, timing chain set, a mild cam and lifters, new water pump, belts and hoses, dist cap and rotor, plugs and wires, air, fuel and oil filters. (I think that's everything.) If you can reassemble the motor yourself you should be able to save some money, and with the block bored over and the cam you should see more horespower. Just to note, sometimes pairing a new engine with a used transmission results in having to replace the transmission not long after.

I bought an ACdelco reman with 36month.36000mile warranty for a 94 Blazer. The valve seats were so bad that the heads both had to be redone under warranty after 30000miles. The AC dealer here has stopped selling these motors because of high warranty claims. I was told they are reman'd in Mexico and they just don't hold up due to cheap parts and soft valve seats. With the new heads at 30000 miles it then started running very bad again at 70000. Leakdown test showed 7 of 12 valves leaking again. I pulled heads myself and the cylinder walls are badly scored. Junk.

I just rebuilt a 4.3 for my 95 for total cost around $1500. (Oil cooler hoses blew, leading to bad bearing) At 100,000 miles the cylinders didn't even need boring, they were still true. $1500 includes machine shop (honing, align hone,complete head job) plus all new bearings, rings, seals, water pump, oil pump, hoses, motor mounts. It is better to rebuild yourself so you can control the quality of parts. Find a machine shop familiar with the 4.3 motors. If they tell you all 4.3's are the same, run out the door and find a better shop. There are incremental differences from one year to next. Light and heavy crankshafts, light and heavy pistons. rings are placed higher up the piston and get thinner as year increases. Mixing parts from wrong years will give an engine that runs, but may have serious balance problems. Used parts must come from the same original GM foundry to work correctly. It's a bitch to get this engine in & out, but don't forget that great "sense of accomplishment " when you do it yourself.
Read this linked article twice before you decide what to do. http://www.babcox.com/editorial/ar/ar40047.htm

Good Luck.