integraguy SuperDork
June 29, 2011 9:00 p.m.

Is there a fairly easy way for someone who does NOT know Chevy engines all that well to tell if the V6 in an S-10 is a 2.8 or a 4.3? I know one is a 60 degree V and the other a 90 degree, and that is about all I know. Is there something about the distributor? The manifolds? The water pump?

I'm asking because I'm looking at 1st and 2nd gen. S-10s and at least 1 or 2 of the 1st gen trucks advertise that they are 4.3 powered. I thought the 4.3 didn't get put into S-10s until the 2nd gen/1995?

KATYB HalfDork
June 29, 2011 9:18 p.m.

i had an 89 with a 4.3.... the 4.3 litterly looks like a sbc with 2 cylinders missing. water pump everything is the same otherwise. 2.8 looks totally diff. as far as i know the 4.3 was always available in the s-10 normally badged somewhere tho as an s-15.

Nitroracer SuperDork
June 29, 2011 9:34 p.m.

I think the S-15 was just the GMC version of the truck before it was called a sonoma.

But with the engines, look at the spark plugs. The 4.3L will have more uneven spacing compared to the 2.8L.


2.8L Google Failed Me

madmallard Reader
June 29, 2011 9:35 p.m.

i think its the same 4.3 used in v6 camaro?

Nitroracer SuperDork
June 29, 2011 9:38 p.m.

Camaros have run the 60* 2.8L/3.4L, and the 3.8L but not the 4.3L.

JtspellS Reader
June 29, 2011 9:40 p.m.

The 4.3 (unless i am wrong) is a 5.7 (350ci) with 2 cylinders lobbed off and that is about it.

June 29, 2011 9:55 p.m.
KATYB wrote: far as i know the 4.3 was always available in the s-10 normally badged somewhere tho as an s-15.

The 4.3 wasn't available in the GM S-trucks (Chevy S10, GMC S15/Sonoma) until '87 or '88. The 2.8 was the one that always available in the 1st gens.

June 29, 2011 10:00 p.m.

Note the even spacing of the exhaust ports on the 2.8

integraguy SuperDork
June 29, 2011 10:01 p.m.


thanks for the tip. I already knew the 4.3 was "3/4ths of a SBC", but needed a better way to identify than just hoping it was obvious that the engine did or didn't fill most of the available space.

I also wasn't aware that the 4.3 was in S-10s before the mid '90s.

jrw1621 SuperDork
June 29, 2011 10:14 p.m. show that '89 was the first year for a 4.3L in a S10.

June 29, 2011 10:26 p.m.

Note the angle of the plugs and wires on the 2.8 pic above. The 4.3 plugs come staight out the side of the engine.

And you really don't want a 2.8 unless you are very, very patient. I could never understand what 5th gear was for in those, unless it was just for coasting downhill...

novaderrik Dork
June 30, 2011 2:30 a.m.
jrw1621 wrote: show that '89 was the first year for a 4.3L in a S10.

they are wrong.. i had an 88 that had a 4.3 factory installed.

the easiest way to tell the difference is to look at how physically big the engine is- the 4.3 will fill the engine bay up from side to side and has an intake manifold that's about a foot wide.. a 2.8 will have a lot of room on each side and the intake manifold is about 6" wide.

jrw1621 SuperDork
June 30, 2011 5:03 a.m.
novaderrik wrote:
jrw1621 wrote: show that '89 was the first year for a 4.3L in a S10.

they are wrong.. i had an 88 that had a 4.3 factory installed.

You are correct. I typo'ed my statement and wrongly wrote '89 which should have been '88.

failboat Reader
June 30, 2011 12:41 p.m.

the 4.3 is an awesome motor. torquey and pretty much bulletproof. accept nothing less.

16vCorey SuperDork
June 30, 2011 1:31 p.m.

TBI 4.3L 2.8L It's kinda hard to tell from these pics, but the 4.3L in much wider (and larger in general). Also the TBI 4.3L will have a ribbed valve cover and the CPI 4.3L will have plastic valve cover that says "VORTEC" on it. The 2.8L will have smooth metal valve covers. And you can see from the pics the pretty obvious accessory placement differences.

slefain SuperDork
June 30, 2011 1:47 p.m.

On the test drive, if you find yourself cursing and trying to push the gas pedal through the floor to get more power, it is a 2.8L. If it drives like it has enough power, then it is the 4.3L.

Driving a 2.8L:

Driving a 4.3L:

Avoid the 2.8L like the plague. I had one, what a lump of an engine.

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