Ok, right now I have a 3.1L V6 in my stock camaro. I have headers for it. I want to do a 4.3L V6 swap, anyone know if those headers would fit? And if I would need a wiring harness and new comp for it? Any fabbing required? About how much is a fair price for a 4.3 motor? Are underdrive pulleys beneficial on the 4.3? I have a lot of questions before I decide to do the swap

 

No, the headers won't fit.
Yes you're going to need the wiring harness and computer, unless you wanted to go carb. You'll need a carb intake for that.
You're going to need a v8 bellhousing and you'll probably need custom mounts done. Take a look at a v8 car. the 4.3 being its a cut down v8 it may use v8 mounts. Or talk to someone who put a v8 in an s10.
There are dozens of s10 in every junkyard I've been to so your local upullit probably has the best deal. I wouldn't pay more than 200 for a good low mileage longblock. Up to you, but if I was doing your build id look for a wrecked typhoon/syclone. Bit more investment up front but you'll be better off in the long run.
Good luck with your build, ill be watching it

 

I would suggest you not do the swap. The 4.3 does not get great mileage nor does it have a lot of untapped HP hiding. I have seen the convertion done before. The guy tried to sell it for a year, he ended up selling the inspected running car for like $500. Heck I almost bought it to part it out.

It is the same amount of work as swapping to a old school V8 just without the HP or torque.

 

Between a 4.3 and a small block v8, the bellhousing is the same and the motor mounts are the same. It would be the same amount of work to put either in, but I'm sure you'd be happier with a v8.

 

I have an L88 350, but I can't use that because of emission laws. However, I'm told in a few years those emissions laws will be going away, and I REALLY need something more than this 3.1L, considering how cheap these motors appear to be, it seems like a good transition, because I can't afford an LS1, or any of the swap parts. Some other people on here said I could get 300 hp outta the 4.3 without a turbo, and I must say I like the sound of that haha.

 

Also, will the wiring harness hook up to my transmission? Again, new to swapping :/

 

if this is your first swap, I'm going to suggest you stick to a 60deg v6, or even a 3.8. There's a guy over at 60degreev6 getting 275hp na, and I've seen grand prix pushing 300+ without the hairdryer. Both have stock bottom ends that will hold up past 400hp. Not gonna happen with a 4.3.
Both will be simpler, lighter, and get better fuel economy. However, if you're stuck on the 4.3, go for it by all means

 

I'm not sure where you live, but I would not count on emissions laws or testing to go away. It is too large of a revenue source for the state/county you live in. On 96 and newer vehicles, they simply plug into the OBDII plug, and most of the time the cars pass, so its a simple plug in then waiting with their hand out for your $12 for emissions, then whatever your state does for registration......For those of us who want a custom car it definitely has made motor swapping difficult, but as long as you research it, and call the emission station they'll tell you what is required....too much money on the table if you hear what I'm saying.

 

yah your not kiding i paid 25 bucks for an inspection on my truck last week.

i know in ny you can only swap and engine to an engine that was original equipment for the car. for example if the car had a choice between a 3.4 and a lt1 i would have to put either an lt1 or 3.4. most inspection stations will give you crap though so i wouldnt do a swap on any thing odb2 in ny. ODB1 is visual only no computers.

I know a lot of states when the car is over 25 years old they dont do any emissions testing at all though.

 

There is a lot to this type of swap. The "wiring" the transmision has it the TCC. As long as you use a transmision from the same era (not sure of how large the era is) the wiring should be the same. I am trying to remember but I do not think that year has a replacable bell housing so you will need a tranny also.

The bigger issues will be the fuel system ( your 3.1 runs MPI runs much higher pressure then the 4.3 TBI. Your going to need the fuel pump and lines for a 305 TBI system. Since the 3.1 has a DIS system the 4.3 does not your going to need the computer system from the 4.3. Exhaust system, mostly headers will need to be made unless you go with stock manifold (you will not get 300 ponies thru those)

First thing you want to check out is the emission laws. The law may state factory emission system must be intact but since GM never put a 4.3 in a Camaro there is no factory emmision system. There is no provision to installing a non-factory motor in a car unless it is a complete emission approved drop in. In some areas even installing a 3.4 block into a 3.1 is a no no. Although I doubt any mechanic would figure it out.

The price of the motor may be cheap its all the other parts that will nickle and dime you to death. I have been helping and doing these types of mods for 30 years, These days Any mod that is cheap and a decent upgrade will be done 1000's of times. Like the V8 in a s10. Its cheap and easy. 4.3 in a Camaro is not common, the reason? It does not make sense. If you want to do it to be different thats cool but to do it to "Save money" it is a huge mistake. Look at a 3.4 upgrade or just go with a V8. In the end the V8 upgrade WILL cost you less.

There are tons of "unfinished" project floating around, many have low miles or rebuilt small blocks in them already. In some cases you can get these projects real cheap use the parts you want sell off whats left and get everything you need for just a few hundred bucks.

Edit: I just checked out my local Craigs list. This is what I am taking about. 600 for the whole project. I'll bet you would have 3-$400 worth of parts to sell once you where done.
http://allentown.craigslist.org/cto/2386818908.html