OBS v. NBS 4.3L

OUMike · January 14, 2004

Hey all ,

I recently ran into this article:

I have a 6 cylinder 4.3 motor purchased new from General Motors and has 12,500 miles on it. This motor is complete from intake to oil Pan with throttle body intake. ( no front accessories ) $ 400.00 for all, including radiator, fan shroud and hose Can deliver if you can load it.

$400 for complete motor sounds pretty good. What other parts would I need to complete swap? More importnatly would this motor that apears to be from a 1999-2002 Silverado bolt to 94? Any insight or thoughts much appriciated.

99-2door · January 14, 2004

The 4.3L motor is the same 96-02. The NBS and OBS vortecs are identical with the exception of a few pieces. None of these motors will be a direct swap into your 94. You can purchase a intake manifold that allows you to run your factory TBI set-up on the 96-02 Vortec motor. And yes, your 4.3L may say Vortec on the valve covers, but it is not the same as a 96-up Vortec. Everthing will bolt up the same as the blocks are the same. IMO though, once you are swapping engines you may as well swap a V8 in there. That does take a lot more work though and you may be happy with the performance of the 96-02 4.3L

Cool Zr2 · January 15, 2004

I have to agree, putting a newer 4.3 in there isn't going to get you anymore power. Unless you convert a obd 2 vortec to run in a obd 1 truck, which would cost as much as putting a 96 and up vortec v-8 in there.

that tbi vortec you have has the same head design as the 96 and up vortecs, so if you throw a tbi conversion intake on it you are not gaining anything.

A v-8 swap would be awesome, you have a tbi system, the only thing you have to do to get the motor running in your truck as far as computers is to switch the PROM chip. YOU DON'T EVEN HAVE TO MODIFY THE WIRING HARNESS!!! Go get some headers, mounts, fans, and exhaust and you are in business.

OUMike · January 15, 2004

Well my body isn't in great shape. Its been hit a few times and sags at the bed and cab. I think its bushings or something that have worn out under the cab causing it to sink a little. So it isn't like a truck I was gonna motor swap for power, just longevity. I was gonna swap motors to get more life out of the truck. But it does seem to be a lot of work.

The way I understand it, the V8s will NOT bolt to V6 4L60-Es. Anyone?? I do believe this is a topic we've exhausted before and the end result, was that the trannys were slightly different.

99-2door · January 15, 2004

I have never seen anything to suggest that the V6 tranny won't bolt to a V8. Then again I have never tried it. I always swap Engine tranny combos (not for any reason, just happens to work out that way).

Is there something wrong with your engine or are you just looking for more power?

OUMike · January 15, 2004

Truck is actually pretty strong. Its a 94' w\ 165k on the odometer. I was just lookin' for a little more life. Not really sure how long to expect the ol' 4.3L to last. I would actually love to purchase a 96-98 like the one that I have (with the 5.7L of course.) Turns out that kinda truck is really hard to find.

99-2door · January 16, 2004

Truck is actually pretty strong. Its a 94' w\ 165k on the odometer. I was just lookin' for a little more life. Not really sure how long to expect the ol' 4.3L to last. I would actually love to purchase a 96-98 like the one that I have (with the 5.7L of course.) Turns out that kinda truck is really hard to find.

In that case, I have a 97 GMC SLE shortwide 5.7L Auto, G80, dual flow 40s for sale

OUMike · January 17, 2004

GMC...bummer. I never really caught on to those front ends until the NBS ones. Got any pictures? What are you asking?

CapnDean · January 18, 2004

Okay...Lemme get this straight:

$400 gets you a motor with 12K miles, and all the stuff you need including the radiator?

SOUNDS too good to be true......Check it out thoroughly! If it checks out...I'd do it even if it cost me another $500 to make it run (swapping old to new computer etc..)

Some folks just don't realize that $1000 nowadays is equal to about 3 car payments. If you could drop that money in the ole beast you'd probably beat another 3 or four years out of it. Call me crazy but the heck with a V-8 conversion...if the six has been enough all this while....

Much as I like my truck we have to face the economic reality:

Automobiles are POOR investments. They depreciate sooooo rapidly that it is best to keep that sucker as long as you can! (I am assuming that at 165K miles on a 94 W/T....you aren't making payments no?)

Do the swap if the motor really only has 12K!

OUMike · January 18, 2004

actually my truck isn't a W/T, its a Silverado , but the ariticle said something about having everything including radiator, but minus front parts. Front parts?? WTF is that? I dunno, sounds kinda fishy to me too.

CapnDean · January 18, 2004

I'll betche front parts are the fan assembly, prolly the PS pump & the a/c compressor...that kind of stuff (at least that would be my interpretation).

Look man...IF That motor truly has 12K miles on it....and isn't blown or something.... I would seriously consider it. $400 is cheap for a good running take out. If the seller could convince me that it came out of a new truck and the owner decided he wanted more power say.... so he dropped an 8 in there... I'd jump on it the heck with the few dollars I would have to spend to accomodate the differences in the motor you have.

But...That's a big IF!

I suppose if I snatched a 6 out in favor of an 8 I wouldn't be all excited about keeping that 6 lying around either so I'd probably let it go for whatever I could get for it (knowing that there is not a huge market for 4.3L motors).

Keep looking into it - - It sounds really good hence maybe too good....but I would check it out for sure....heck...what could you lose? $400? If your 165K miles truck will hold the new radiator, and you could cannibalize a few other parts off the motor... EG starter, water pump, etc... you could even come close to recouping the 400 WITHOUT installing that motor...

Good luck.