S10 4.3 swap

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
So I've got an '89 s10 that i love to death. Just your regular run of the mill single cab short bed, 2.5 iron duke, 5 speed manual trans, 2wd, throttle body injected yada yada. I bought it 3.5 years ago for $650 bucks for my daily driver. I can't complain one bit as it's paid for itself 10x over in fuel and maintenence savings. Had 94k when i bought it and currently has 117k. It's never left me stranded and has ALWAYS fired right up. Gets 24 mpg and is quite comfy in my opinion. I put a radiator in it about 2 years ago and a heater core yesterday....that is the ONLY issues it's ever had.

The thing is slow as balls and with any weight in the bed and the ac running it makes for an interesting drive.

I've been wondering if swapping over to the same era 4.3 liter is doable. These trucks are a dime a dozen at the junk yard and i could get a motor for nothing. Any one ever swapped in a 4.3 into an original 2.5 truck? Would the 5 speed trans and rear axle hold the "upgraded" power?

If it's an easy/cheap swap I would start gathering parts ASAP. Even a bone stock TBI 4.3 in this little truck would be pretty fun.
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
Here's the ol' girl...can use a paint job obviously. I've just been rattle canning it flat black since I bought it. The body is in great shape other than 2 bullet holes in the tail gate and a dent in the bed side. Damn near zero rust.

20140326_152106_zps1d7846a5.jpg


Interior is pretty good, dash has a crack in it and drivers seat is worn. Other than that's, it's golden. Had to make some custom cup holders.

20140326_152132_zps6dc64473.jpg
 

Muff

Just Learning
Oct 7, 2013
1,063
0
36
Butler, Pa
Suicide knob! SAWEEEET.

If this truck is problem free and you've drove it the way it is for 3.5 years why change it now? As soon as you swap that 4.3 in your gonna have problem after problem. Going fast is what your dmax is for. JMO
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,008
4,582
113
Phoenix Az
the 160hp 4.3 wont make this thing a rocket ship lmao

I have no idea on the trans but the motor should drop right in with new motor mounts. you may need a bigger radiator so id research on that. A/C lines may be a bit different as well if the compressor for the 4 banger isnt on the pass side and at the top of the accessory drives. I dont think you need to swap harnesses, pretty sure its all plug and play. you will need the 4.3 injectors though and a new chip flashed to put in the computer unless you have that awesome weird coded one that you cant remove the chip from. New exhaust will be needed, possibly a new fan shroud, and maybe a few other little things like hoses and what not

you will like the low end grunt from the 4.3. id do the swap for sure. that little 10 bolt will be just fine.
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
Suicide knob! SAWEEEET.

If this truck is problem free and you've drove it the way it is for 3.5 years why change it now? As soon as you swap that 4.3 in your gonna have problem after problem. Going fast is what your dmax is for. JMO

Suicide knob makes up for no power steering. Works like a charm.

That is a very valid point and if the job was even remotely challenging then I would forget the whole idea. I just want it to be a bit more peppy:roflmao: not happening with the 2.5 in there.
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
the 160hp 4.3 wont make this thing a rocket ship lmao

I have no idea on the trans but the motor should drop right in with new motor mounts. you may need a bigger radiator so id research on that. A/C lines may be a bit different as well if the compressor for the 4 banger isnt on the pass side and at the top of the accessory drives. I dont think you need to swap harnesses, pretty sure its all plug and play. you will need the 4.3 injectors though and a new chip flashed to put in the computer unless you have that awesome weird coded one that you cant remove the chip from. New exhaust will be needed, possibly a new fan shroud, and maybe a few other little things like hoses and what not

you will like the low end grunt from the 4.3. id do the swap for sure. that little 10 bolt will be just fine.

By no means am I looking for a rocket ship. 160hp is a huge step up from its probable 80 horse it has now. Would the 4.3 bolt right up to the trans/clutch/flywheel? That's my main concern...if I have to find a new trans and axle, I won't mess with it.
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
Ac compressor is on the driver side at the very top of the accessory belt loop. No power steering so dont have to worry about that. Radiator and hoses are no big deal. As far as the computer goes, I could just snag one from a 4.3 truck.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,008
4,582
113
Phoenix Az
i would doubt the clutch and fly wheel swap over. look up s-10forum.com. they had all kinds of info on that motor and those kinds of swaps when i was looking for info on doing the 4.3 TBI in my old buggy project.
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
i would doubt the clutch and fly wheel swap over. look up s-10forum.com. they had all kinds of info on that motor and those kinds of swaps when i was looking for info on doing the 4.3 TBI in my old buggy project.

Alright I will browse around. I did a little search g and most all I could find was people swapping out old 4.3's for vortec 4.3's. If the typhoons and cyclones werent 9 grand still, I would have one of those as a daily driver.
 

turbo_bu

Member
Mar 27, 2007
191
6
18
Central IL
Bell housing will be different, but you do have a T5 tranny in there. BTW, you think your 2.5 is slow ... take a 2.2 for a spin :(. I used to have a 91 dime, but it was getting long in the tooth and rusting too badly. Currently rowing a 99' with a 2.2L in there. Man, do I miss my 2.5 and T5 setup. It also never left me stranded :)
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
Bell housing will be different, but you do have a T5 tranny in there. BTW, you think your 2.5 is slow ... take a 2.2 for a spin :(. I used to have a 91 dime, but it was getting long in the tooth and rusting too badly. Currently rowing a 99' with a 2.2L in there. Man, do I miss my 2.5 and T5 setup. It also never left me stranded :)

Guess i cant complain about the 2.5 then.
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
I was impressed by the cupholder at first, but then I saw the tow mirrors for the win. :thumb:

Some jack Wagon ripped my driver mirror off one day so I drove it for a couple months..then registration was due, remembered the original mirrors I had off my 02 lb7, with little modification they fit right on:roflmao:
 

DieselS10

New member
May 12, 2009
97
0
0
Oklahoma
As mentioned the bell housings are different, and most everything else attached to it. If you could pick up a cheap donor that was wrecked or just horribly rusty it would be far easier IMO.

I can also relate on that beast of an engine your running, my truck was originally a 4wd long bed with a 2.5/4 speed. You could easily out run it on foot in the 1/4...
 

BIGTERRY75

BIG T
Jul 15, 2014
35
0
0
ROCKWALL TX
LS engine and trans can be bought cheap. I've had a few of these lil trucks and v8 power is the only way to go.

Way back in the day I had a carbed 355 with some junk ass heads on it. Got great mileage when cruising. 20+ depending on cruise speed. 80 would get you 18 ish.

That being said the LS engines are far more efficient and the power is awesome.
 

K1SSRSS

Dieselfied Camaro Junkie
Jun 26, 2014
41
0
6
Las Cruces, NM
I have both a blazer with a 4.3 V-6 swap in it and a S-10 with a V-8 conversion. The kicker is it's about the same amount of work for either. The difference is that T5 will hold up to the 4.3 and not likely to the V8 unless you go with something like a 305.

To go with the 4.3 you should be able to keep your stock tranny, you will need motor mounts, wiring harness, computer, bell housing, exhaust and depending on if your current set up is fuel injected or not, you may need a high pressure in tank fuel pump. To simplify things depending on emissions in your area you may just want to go carbureted either way.

Like Bigterry, my original set up in my s-10 was a warm carbureted 355 also and I was able to get about 20mpg with a TH350 auto and factory gears, on the blazer I can see 22-24mpg but it is heaver, 4wd and was a little more of a pain dealing with the EFI.

I think the ideal set up for a DD would be a stockish 350 or 327 with an OD tranny and I bet you could see 25mpg and have all the power you could ever want.

Of course a LS 5.3 or 4.8 would be sweet too, but there goes more work, I am currently doing a 5.3 turbo swap on mine but every time I work on it I wonder why I didn't just go with a 400 sbc build.

One last thing I forgot, likely with either the 4.3 or V8 you will want heavier springs on the front end.

What would be kinda cool and pretty simple if your just looking for a little extra hp is to fabricate a small turbo set up for your current engine. Just find a junkyard turbo 4cyl car grab the turbo and piping, fab a turbo exhaust manifold and there you go. Ideas, Ideas. lol
 
Last edited: