I have a '94 Grand Am with the 3.1 that has a BAD knock in the lower end..
So, instead of fixing it i was going to see if i could use the injectors to replace my worn out 2.8 ones.

Would they be a direct fit? I know they are both rated at 15 lbs..

Also, besides the whole hybrid build, are there any other parts i could use to benefit my lil 2.8 of fury?

If, and I seriously doubt this, as the J-body Cavalier and the Sunbird were the only cars in 94 that had the 3.1, your Grand Am has the MFI 3.1 and not an SFI 3100, then yes, the fuel injectors will work. If the GA has a 3100, however, you'll only create more problems for yourself, as the fuel injectors are actually rated at 18.4#. I ran a set of those by mistake on my 3.1 and it ran rich, so your 2.8 will probably be the same way.

Other than that, no, your GA has nothing you can use on a 2.8 without modifications to the ECM and other things.

Ok, You are right, it is a 3100 sfi.. But after doing some research all the sources say they are rated at 15#... Edit: and 17#. lol

And i didn't think anything else would work, just was curious.

What's the part number on the injectors? The number will be stamped into the housing near the electrical connector. If the injector part numbers are NOT 17084888 or 17089569, which are both 15# injectors used on both FWD and RWD 3.1's, they won't work without tuning.

I will try and check them tomorrow.

Chances are Mav is right, Because I seem to recall 3100s using 17 or 19#, and 3400s using 22.5#, and know for a fact that our 2.8s are 15#, so without ECM tuning or a somewhat built engine, it will run too rich, foul up plugs, waste gas, etc. if it runs at all that is.

Oh, it'll run, just not very well. 2.8's also used 15.4# injectors, same as the 3.1, in 88 and 89, with 87 being the crossover year.

Ok.. I just don't feel like paying around $50 per injector new..

Hmm, 15 to 15.4 wouldn't matter though, That's a pretty minute difference, didn't know that though, just out of curiosity here, am I right about the 3400 using #22.5, cause I've only read that once, and am not sure if it's entirely accurate or not.

You can get a set for under 200, like 160 or 180 I think, or you can try finding used ones, I've got a set I might part with...I can't promise how good they are cause the engine didn't run due to bad HGs when I bought it. But theoretically assuming that was the only problem(I suspect there might have been a vac hose leak, and the timing off, cause it wouldn't even start) they should be fine. All of that being said, I'd probably part with them for like $40 plus w/e shipping, so if you want to roll the dice let me know, but even if just one works you'd still save money over $50 per.

you can get a full set of aftermarkets for under 150...i got a set of bosch gen 3s from southbay for around that

87 had a choice between the RP 523-5210 (what mine was running with pintle caps) at 14.7# and the 523-5136 Multitec style at 15.4#, so, either or, I suppose. Yes, the 3400 DOHC is rated at about 22#, according to the N-body OBD1.5 to OBDI swap guide I have.

OP, check eBay... They usually have cheap sets there. Sometimes they're remanned, sometimes just yanked, and you need to make sure that they aren't for a 3100 by checking the year.

3400 what? :P

Dual OverHead Cam... Actually seen one in the j/y, but it's a 93 with the famous 49396 ECM (and still MFI... ). Not sure about the 3400 SFI, you're probably right.

Yeah, I was referring to the fact that I'm almost certain the correct name for it is 3.4 DOHC and not 3400...at any rate when I asked about the lb/hr rate I meant for the 3400 OHV engine, but they might be the same for all I know, I'm kind of curious how far these injectors can get me in a built engine before I need bigger.