engine swap

i am looking to swap out my 3.1 liter with and 4.3 vortech. would i have to change the trans or would it hook up and what eles might i need to do.

You'll need a new trans. Your 3.1 is a 60 degree block, the 4.3 is a 90 degree block, so the stock transmition won't match up to the new motor. (That is assuming you have an automatic trans. I'm not sure about the manual trans.)

To install a 4.3 you'll almost be doing as much work as it would take to drop in a 350. If you just want to keep it a v6 the 3.4 litre might be something to look into. The 3.4 is a 60 degree block too, so you would be able to keep most of your origional stuff.

would the 3.8 litre fit the 3.1 litre trans or would i run into the same problem as the 4.3.my firebird is and 1992 3.1 automatic with overdrive.

Unfortunally, no, the 3.8 won't work with your trans either. The 3.8 is a 90* block. If you really want to use your trans you'll pretty much have to stick with a 60* motor (2.8, 3.1, 3.4).

Even though the 3rd generation V8 Firebirds and Camaros used a 700R4 too there are differences between the 700R4's that were used in the V6's and V8's. The 700R4's that were made for the 60* V6 had a different bellhousing than those that were made for the 90* V8's and 90* V6's (3.8, 4.3). There are some internal differences too, but I'm not really sure as to what exacly they were.

would i be able to build the 3.1 to get some decent horsepower? and what could i do.

You should be able to sqeeze a little more power out of the 3.1. One of the first things that should be done is a good tune up plugs, wires, distributer cap, and rotor, fuel filter, etc. A different cam (such as a Crane Cam 2030 if I remember correctly) or a new exaust system would help. I've heard not to go bigger than 2.5 inches on the exhaust. There is a catback exhaust sytem made by Dynomax that is a popular choice for these cars. Leave some sort of catalytic converter on the car though. Last summer, I took mine out temperarily (for about a month) and replaced it with a straight pipe and for some reason the car wouldn't start as easy as it used to. I put the catalytic converter back on and it started fine agian. Headers would help out too. However, no company currently makes headers for these cars. I have heard of people using the 3.4 headers for a 93 - 95 Fbody in a 3rd gen car, but they have to be custom bent in order to fit the engine bay. I don't think that any comany makes a supercharger for the fuel injected v6 3rd gens, and any turbo settup would have to be completely custom.

Another option would be to swap in a 3.4 out of a 93 - 95 Firebird or Camaro. (95 was the transition year from the 3.4 to 3.8, early models had the 3.4) The 3.4 will bolt up to your trans, and you would be able to use most of the stuff from your 3.1. You are basically taking the 3.4 long block and dressing it as a 3.1. For a little more info about the 3.4 swap go to this article on www.thirdgen.org http://www.thirdgen.org/newdesign/tech/swapboogie.shtml
Your 3.1 has about 140 hp and 180 ftlbs of torque. The 3.4 has 160 hp and about 200 ftlbs of torque. I personally plan on swapping a 3.4 into my 84 Firebird after I'm done with college. To me the 3.4 seems like a decent power gain for the money.

Just keep in mind, a V6 just isn't going to run like a good V8. Trying to make a 60* V6 a really fast car would be expensive. It can be done, but its just not worth putting tons of money into. If you want to build a road rocket you'd be better off starting with a V8 car. Save the extra time and money that it would cost to convert this car to a v8 and use it to buy a car with a v8 already in it. I know that these cars feel slow, but they are good looking cars, handle very well, get decent gas milage, and most importantly of all: are fun to drive. Just accept your car for what it is and do your best to keep it running reliable and looking good.

would it be possible to have the heads milled onthe 3.1 have hardened vavles and change the intake and exaust and use diffrent pullyes to gain horsepower?

I've heard of people doing just about everything to a 60* v6 that you just mentioned exept the hardened valves (not saying that it cant be done). Doing all of those things to your engine would probably increase the power some. Hard telling how much power you'd gain exacly, but I doubt that it would be all that much.

As far as changing the intake, do you mean change the intake manifold, or the ductwork going to it? I don't think that any company makes an aftermarket manifold for the rwd 60* v6. If you want to change the tubing going to the intake, you should be able to search the internet for some ideas on how to fabricate a cold air intake yourself. I'm not too familiar with the 3.1, but I don't think it has the MAF sensor to worry about if you fabricated your own cold air intake. I have heard of guys replacing their trottlebody for one that flows more, but most people agree that it will only be worth it on a fairly modified engine.

Before buying underdrive pulleys for your car make sure that your alternator will still be able to spin fast enough to be able to charge the electrical system. Some say that they do help a little though.

I'm not sure what the hardened valves would do though, please inform me. I thought that all engines that use unleaded fuel use hardened valves.

if i swiched to the 3.4 litre what would i be able to keep or what would i have to change to use this motor.

To use the 3.4 you would need the 3.4 block with all of its internal parts, the 3.4 heads, 3.4 exhaust manifolds, and a set of 3.4 fuel injectors. You're basicaly taking the parts mentioned above and using them to replace your 3.1 parts. You still use your 3.1 intake manifold, fuel rails (with 3.4 injectors), and distributer. You still use all of your origional sensors too, so you can still use your origional computer.

The one link that I mentioned above will help answer a lot of your questions. http://www.thirdgen.org/newdesign/tech/swapboogie.shtml
You might also want to look at the V6 forum on www.thirdgen.org several guys there have done the swap already. Just do a search on that site and you'll fine tons of information about the swap.