Replace 3100SFI w/ 4.3 Vortec...? *pics

[98MalibuLS]

I have a 98LS 3100sfi that needs a new engine & I also have a 4.3 Vortec out of a 2000 Jimmy that runs...anyone know if it's possible to bolt it to the existing auto tranny?
I'll do it if it's possible, I need to get both of these things moving somehow
here's the 4.3

& the ruined 3100sfi...


check out that head!

[AaronGTR]

The 4.3L vortec V6 is a 90 degree block. It's from the same family as the 3800, and I can't be 100% sure, but it should share the same bolt pattern on the block. We already know that the 3800 and the 3100/3400 motors will bolt to the same transmissions so I would think that the 4.3 would as well. You'd just have to make sure you have the right torque converter for the trans and if it will bolt to 4.3L flywheel.

Engine management will be the hard part. The wiring harness and pcm will be totally different. You could make it work, but will it be worth it? Are you going for performance and do you really need the displacement? And will the trans handle the extra torque from the bigger motor (probably not). I'd just look for a used 3100 to put in it, or go to a 3400 (should be almost a drop in affair from the 3100-->3400). You can find them both cheap with reasonable miles from a junkyard.

[98MalibuLS]

I have all of the wiring & the computer for the 4.3, I also have factory service manuals for each vehicle, I'm fairly sure I could do it as long as there's no major cpu compatability problems.

also, the engine was bolted up to a 4l60e...

[onefastV6]

I personally think it would be a pretty cool swap. The 4.3L is basically a small block chevy with 2 cylinder chopped off. Performance Parts are abundant and cheap.

The problem areas that I for see are the computer, you could get a tuner probably convert the PCM to run the 4.3L, wiring will probably be the biggest headache along with mounting the engine and fabbing headers to fit, since the 4.3L was never used in a FWD application.

The only downside that I see is the fuel system is a joke, but there are guys in the 12's with the stock fuel system on S-10's.

[sharkey]

the 4.3l is not in the same family as the other 90 degree v6 motors, its a family on its own. the other 90 degree motor (3.0, 3.3, 3.8l) are all buick based motors. the 4.3l is litteraly a 350 with 2 cylenders cut off. it uses a v8 bellhousing bolt pattern, and many parts are interchangable with a 350.

no, there is realy no easy way to put it into a fwd. im sure you could use an adaptor plate for a smallblock fiero conversion, and build custom mounts, caccessory brackets, ect and make it all work. in the end you have about 190hp and 250ft/lb of torque, something atainable with a 3400.

[98MalibuLS]

& how much $ would we be talking? I'm not looking to spend any more than $1000. I can weld & machine a lot of my own parts so I'll have to see about making an adapter.

[geoffinbc]

Dont bother. Cheeper to get a new 3100/3400 from a junkyard and drop it in. Plus the #xoo motor makes more power. Is GOBS lighter and I dont think the 4.3L would fit in the engine bay of the Malibu it is a hell of alot wider.

[Ortie666]

Doo it, u juss answerd ur own question.. u can weld, and machine. BOOM a swap technician. think of it on the bright side 190 hp is wimpy but a i think a 396 makes a little bit more than that, (chop some frame to fit 2 more cyl and ur laughin' !!) lol dont listen to me

[Weston19]

Ughh, you do realise a 396 is a bigblock? lol

Now 383 sbc stroker with a Vortech blower.............Your laughing.

I think the 4.3 is too long to fit in there anyways. The adapter plate and with the accesories, i think youll be in the wheel well.

Colin was considering a n* v8 swap into his car. He even bolted up the trans and did a test fit with no accesories or intake. It was too big.

[Ortie666]

My bad, I was thinkin a juiced 400 smallbock. Well you see, if you were to shorten the drivers side axle and make frame wider, then you could possibaly have it fit. just dont be afrade to mame some stuff.

[El_Diablo]

there was a guy who put a N* in an old v-dub... it was a golf or something, just a 2 door hatch.... it will fit, i garuntee it, they have less space than us and all he had to do was chop a lil off the header for the front bank

[Blue89rs]

How big is the throttle body on that 4.3???

[El_Diablo]

70mm IIRC

[Blue89rs]

It looks way bigger than that. You sure?

[El_Diablo]

im pretty sure its either 70mm or 75mm.... i could always be wrong though