Just curious but all i've found on this board is some type of fuel injected 3.4L swap... is it possible to do it with a carb? Or would i just need to use the ECM & etc from the 3.4 and go that route?

Thanks

 

If you are swapping your 3.4 in place of a 2.8 or 3.1, you can use the ECM and wiring from your original setup. The only mod needed is if you have an old 2.8 carb application, because your new 3.4 has no provision for the mechanical fuel pump. You will need to hook up an electric transfer pump in its place. Other than that, you can use either original 2.8 carb equipment, or if you are doing an aftermarket type install, an aftermarket 4bbl intake for a 2.8 will work fine. You will need an early 80's big cap HEI if you want to retro-fit some sort of vacuum advance, too.

Can you be more specific as to what you want to do?

 

I have a Carb 2.8L with an electric fuel pump. I would like to swap in a 3.4L but didnt know if id be able to use the carb or if i would have to go the route of using injectors. The carb is just a standard 2bbl, i think maybe around 300 cfm IIRC. I rebuilt the 2.8 around 6 months ago so its all fresh.

 

Your 3.4 will swap in wonderfully where your 2.8 once was. Since you have an electric transfer pump already, you don't need anything else. Just use the intake, carb, and distributor from your 2.8 and you are good to go!

Even though you rebuilt your 2.8, don't expect it to last, no matter how good a job you did on the rebuild. The 2.8 is not good for a rebuild unless it is 1987 or newer. Before that, there was a different main size every year until they got it right.

I swapped a 90 3.1 fuel injected engine in place of an older 2.8 carb application, re-using all of the carb stuff, and it was a great swap. So, no worries!!

Good luck!!

P.S. Also either buy an aftermarket cat-back exhaust or use a factory V8 setup to get rid of your original, restrictive stuff. Then have an exhaust shop make you a real y-pipe and ditch your factory junk y-pipe as well. You'll be glad you did!

 

Yeah, i don't like the 2.8 at all.. i feel like i wasted the money rebuilding but there was a rod knocking and didnt even consider a swap at that point. It probably would have helped to mention that i do have an aftermarket exhaust. I'm running 2.5" pipes with no cat to a flowmaster exhauster with dual 3.5" tips.Quick question tho.. will the parts from the 2.8 decrease the performance of the 3.4?

Oh and will the v6 t-5 bolt right up?

 

The parts from the 2.8 won't decrease the performance of the 3.4 engine. You may need to slightly increase the jet size to make up for your increased displacement of your new engine. That is something you will notice after you are up and running.

The real increases that you feel will be from the newer technology on the 3.4 engine. The cam is a better profile; even though it is optimal for the fuel injected application, it works great with the ECM and computer controlled carb from the 2.8v6. The heads are better, as are the exhaust manifolds. You are only going up.

You will need the 3.4 flywheel for a manual trans, the 2.8 piece is different. The trans and bellhousing will bolt right up to your 3.4.

 

would it be best to switch over to using injectors or keep the carb setup? The car is a daily driver to school and work if that helps.
Thanks for all your help bro

 

Simpler is better, in my humble opinion, if the car is to be a daily driver to school. Unless you have a backup car, don't try swapping to fuel injection just now. Just drop your 3.4 long block in, and start with that. If you end up with a winter car that you drive every day later on, you can then undertake the swap and be assured that you will still get to school or work on time. This is advice from someone who learned the hard way...

Good luck, whatever you do...

 

yeah well as of currently my car hasnt seen the road since the beginning of december. I got it into the garage to do some work.. didnt start the work till a week or so later. Did the work.. then got a bunch of ice on the yeard for a few weeks and wasnt able to get it out lol.

But what's stupid tho is the guy i bought the car from put in a 2.8L from an '86 S10, had the balance knocked off the flywheel, and threw a rod in it. Then i bought it.

So if i do the 3.4 Swap just pull the 2.8 block out swap the parts to the 3.4 and some of the parts from the 3.4 and put it back in as if it were the 2.8 and should have no problems?

 

yes, you're going to make the 3.4 look exactly like the 2.8, w/o the knock

 

sweet. The 2.8 runs strong for what it is but its not enough. And with the newer 3.4 block i should get better gas mileage out of it. Do the make vortech heads that'll fit the 3.4?