The Chevy 4.3.....pros? cons?

I don't really consider myself to be a "Chevy guy", but it looks like I've finally narrowed my potential next "new to me" car to a mid '80s OR early '90s Chevy with the 4.3 V6.

Both of the vehicles I'm looking at are trucks (of a sort) the older one is an El Camino and the newer one a Silverado. The El Camino has the almost obligatory automatic and the true truck has a manual trans. I really wanted a 4wd, if it was a real truck, but Chevy prices are much higher for the equivalent truck, than a Ford or Dodge.

Both, not that I'm buying both, would be light haulers....trips to Lowe's or the recycling center type of duty....with an occasional long trip.

I had a 91 S10 with a 4.3 5speed and I wish I still had it. The 4.3 has tons of torque and would blow most any Camaro or Mustang off the road that didn't have a V8. With a good exhaust set up it sounded great too. The cons to the 4.3 are there are not may go fast parts. Really the only things I ever saw were TB spacers and some headers.

Most of the Chevys that the local SBC uses are 4.3 powered.

There's been quite a lot of difference over the years.

Basically, though, they are tough as nails with few problems. The biggest problems are the Vortec models sucking intake gaskets every 50k or so, and suffering from distributor cap failure at about the same rate. (It's a cross-over cap and it can arc internally, especially if you get a cheap one)

They used to have problems with the fuel pressure regulator dumping into the intake manifold, but I haven't had to do one of those in many years, so maybe they've licked that problem.

No idea on the El Camino, other than it's the older generation 4.3l.

Hearsay is that while the 4.3 is awesome in everything else, it sucks in full size trucks. Noticeably less power than a 350, without much better fuel economy.

That's the hearsay, at least.

so it would be perfect for a light hauler s10

Pretty sure the 4.3 is the same as the 350.. but without the last two pistons. Since that is the case, I'd imagine some of the parts would be the same ( rockers, valves, springs, pistons, rods, bearings) You'd only have to buy 3/4's of the parts of a v-8. Edelbrock makes a intake for the v-6 as well.

As already noted, I can't categorically say an early 80's 4.3 is the same as later versions - like those found in 90's vintage Chev and GMC trucks.

My DD is a '96 Sonoma with the 4.3 and it has been very reliable. Then again, this is a 14 yr old truck with only 80k miles and wasn't/isn't abused to any degree. The engine has been extremely reliable and only ancillary items (water pump and alternator) have needed replacement.

Mileage is not great, but not too bad for a 3800lb vehicle. Averages are 18-19mpg around town and 22-24mpg when interstate cruising at 65-75mph. The numbers are likely to go down for a full-size truck.

While both the Elky and the Silverado would work just fine for light hauling, I'd recomment the one that would be easiest for finding parts at lower prices - and that would be the Silverado.

My 4.3 has 392,000 Km on it it, and it's never been apart. I've done the water pump once, but that's it for repairs. It's on its second set of plugs, original wires and cap even.It's in an Astro that has served as my tow vehicle for a decade. I've got nothing but praise for the old beast.

Oh yeah, I forgot my family and I owned a farm in the 80's and 90's and we had a full size pickup with a 4.3 and it did just fine. We hauled silage wagons and it never missed a beat. It did have a 4 speed with a granny-low so that prob helped. There is no telling how many tons of feed we hauled with it and it took all the abuse.

stay away from the early (92-95) vortec 4.3s. They have some serious issues. Injector, #1 cylinder ovaling out.
The 4.3 TBI motor OTOH is a stout but boring motor. not much HP but makes up for it in grunt IMO. Had one in my 91 Blazer and my brothers 92 Bravada.

what year truck?

the 96+ vortec 4.3 is a beautiful engine to drive with, had a 97 1500 2wd with it and it felt way better than the 96 vortec 305 a family member had. i hauled lots of stuff with it and even towed a 74 impala.

the TBI 4.3 in the fullsize trucks(88-95) is indeed boring but it will do whatever you ask it to and do it well beyond 200k miles.

The El Camino is an '84 or '85, so it has a carb or maybe TBI?

The Silverado is a '91 with the "5 speed" manual.

I was hoping the El was a 4.3 V8, but Chevy didn't offer it in the G-body....at least at that time.

I've actually seen Silverado EXTENDED CABS with 4WD advertised for sale locally with the Vortec and automatic. I wanted something inexpensive/cheap, smaller than a strip mall, that had working air, and wouldn't be so oddball (tho oddball is fun) that I couldn't get parts for it. This regular cab Silverado is nearly perfect, 4WD is what would have made it perfect.

I've been contemplating an astro to replace my caravan what years are best for those?

4.3 are just 3/4 350s. I don't think they ever had good heads and you can't (within reason) hack and weld aluminum heads to fit. GM Performance had better heads for circle jerk racing back in the day, but that's long since dried up.

its a workhorse of an engine. Nothing spectacular, but you can not kill it.

OTOH... Took me 2 hours to change the starter on a 99 4x4 4.3 S-10 this weekend. 1/16" clearance to pull it out.

want to see the scrapes on my hands?

The TBI engines are boring, but super tough. The early vortech engines had a lot of CPI issues, among others. The later vortech engines don't have nearly as many problems with the fuel injection, but had rod bearings make out of play-doh, or something equally crappy. We swap out at least two a week where I work.

I remember seeing a HotRod magazine article on a supercharger mated to a 4.3 that made rediculous power...but other than that I'm not much help

16vCorey wrote: The TBI engines are boring, but super tough. The early vortech engines had a lot of CPI issues, among others. The later vortech engines don't have nearly as many problems with the fuel injection, but had rod bearings make out of play-doh, or something equally crappy. We swap out at least two a week where I work.

when did that start btw? I've been seeing them with bad bottom ends regularly myself. And not necessarily neglected or high mileage examples either. always in the s10 chassis though. in the astros there seems to be no trouble

It's a shame they don't make a 6-cylinder LSX.

I had that Hot Rod article.. they made 500 hp on an engine dyno with a supercharged 4.3. BUT, i THINK that was on race gas and with an unstreetable boost level for that reason.

However, thats a supercharger. You know, that thing that's inefficient, doesnt have an intercooler, and is hard to change boost levels on. There are... somewhat better.. ways of generating positive manifold pressure that could probably exceed those numbers in a more streetable setup.

I like the 4.3 but ill only echo what others have said. Skip the middle years unless you accept what you'll be getting into. I also dont have much love for the later years (did a motor in a '00 blazer in june).. So really i guess what i'd be after is something like the el camino you're talking about, or an early Astro, if i had to pick a non-sy/ty 4.3 car.

Id go for the El Camino by far because its cooler. I dont think its any less capable of truck work than an s10 other than that it is less disposable. As for the full size 4.3 trucks.. eh. They're alright to me, much easier to work on than the s10s, but also just reek of mediocrity and anonymity.

hotrodlarry wrote: Pretty sure the 4.3 is the same as the 350.. but without the last two pistons. Since that is the case, I'd imagine some of the parts would be the same ( rockers, valves, springs, pistons, rods, bearings) You'd only have to buy 3/4's of the parts of a v-8. Edelbrock makes a intake for the v-6 as well.

It has an offset-throw crank, so the rods and rod bearings are 4.3l-specific. Other than that, and the timing set (if it has a balance shaft) and timing cover, pretty much yeah.

'Ceptin' it's not the last two, but two out of the middle. 3 and 6, I think.

I was recently entertaining the thought of a 229-powered RX-7, and so I'd been doing research on the buggers. Consensus was, just find a Vortec 4.3, everything is leagues better.

But... the 229 was odd-fire. I want an odd-fire V6 that you can have a snowball's chance of finding parts for, unlike an odd-fire Buick. (Step 1: Actually try and locate an odd-fire Buick)

kreb wrote: It's a shame they don't make a 6-cylinder LSX.

It's called the 3800 Series II.

I'm not kidding... the Gen III Chevy was developed out of the good ol' short 3800. Crossbolted mains, rear block plate, front mounted oil pump... all that it's missing are the dry intake manifold and separate intake manifold/valley pan. But then, that doesn't make much sense on an iron block engine, that's a lot of additional weight for a little bit of leak prevention.

And the Gen IIIs do leak oil eventually at the valley. Have been seeing it more and more on vans.

Canoe

ReverendDexter said:

Hearsay is that while the 4.3 is awesome in everything else, it sucks in full size trucks. Noticeably less power than a 350, without much better fuel economy.

That's the hearsay, at least.

That's false depending on many things. Remember that gm trucks were legos for decades and you could get 3-4 rear end ratios, 2-3 different trans per engine plus cabs and bed configurations. 
 

I have had 2 full size OBS trucks (88-98) with 4.3/5-spds. Both were good trucks. Both were easy to run extra legal speeds and compared to their 305 and 350 tbi v8 siblings were absolute fuel sippers. My 93 ECSB would get 25mpg at 70 all day every day. The 89 RCSB was good for 24 at 75. Both pulled trailers at Some point, hauled stones and building materials. The only issue I ever had was the rear lowering leafs didn't have the capacity the stock leafs did so when loaded with 500lbs or more in the bed would ride the bump stops. Not an issue with stock springs. 
 

even the older TBI distributors were finicky about cap/rotors. Brass insert caps lasted best (about 40-50k) and getting good wires to last that long were difficult back in the 90's. But a cap/rotor/plugs/wires every 30-40k for $100 was easy and kept them running like a top. 

Cousin_Eddie (Forum Supporter) said:

Canoe

Damnit ....