1988-1999 4.3 V6 Power, K1500

[moondoggiemn]

Good Day

 

Does anyone know where I can get horsepower & torque curves / plots for 1988 - 1998 4.3 V6 engines used in K1500 trucks?

 

I already know, in rough numbers, that the 4.3 used in 88-92 trucks makes 160hp @ 4000 rpm & 235 lb/ft @ 2400 rpm, the 93-95 4.3 makes 165hp @ 4000 rpm & 235 lb/ft @ 2000 rpm, & the 96-98 4.3 makes 200 hp @ 4400 rpm & 255 lb/ft @ 2800 rpm. What interests me most is what's going on at 2000 rpm, give or take. My concern is that maybe the higher-output newer versions might not make much more torque and/or hp when cruising at highway speed. If this is so, then the higher-output engine isn't necessary & I can buy an older truck. In other words, if I have to downshift for a hill, I really don't care if I go up the hill at 45 mph or 60 mph. So, if the newer, higher-output 4.3s don't make appreciably more power at cruising speeds, I don't need the newer truck.

 

Thanks & Blessings!

[barry G]

The changes are about stamina.

same as the v8...or four cyl.

obd2 was 1996. That is multiport injection, real computing, wideband, dual bank monitoring with final trim...even a cat checker code, ability to monitor live data.

An alternator control is also in the mix.

No more over volting.

cold starts have 55psi, and great for hot weather..full return system.

 

another fact of change beyond hp..

the timing ramps. they stay precise enough to make it feel like more hp beyond the greater hp it really is.

The last 305 was multiport, and is in the top 3 greatest powers of all smallblocks since the 265.

 

Multiport did alot. Roller lift, bigger cams.

 

From carb 5psi to TBI 15psi to MP injection at 55psi..I have had it all on one gm motor.

I am not looking back for real world.

 

multi port all the way.

 

You'll find the TBI on the 88-95 goes a bit weird when you don't want it to, and EGR goes way active on long demands.

Great plow trucks, or slow local runs to a hardware store or something.

[ifixedit]

Unless someone actually dynoed each vehicle / engine option in question I doubt you'd find much more than the published info you already have. Try search the internet for dyno results, you might luck out.

 

One thing to remember is the old saying "there's no replacement for displacement" and although in this case yes we're talking the same size engine, we're also talking a difference between 35 and 40 HP which you will feel seat of the pants, also in improved mileage and longevity as the higher output engine although still very tame will be stressed overall much less. I too had a TBI 1988 Silverado, hated it, the damn thing couldn't make up its mind what gear on the highway it wanted to be in, and even the slightest puff of a head wind and the thing was constantly back shifting, most likely to compensate for the lesser overall power output which would drag the truck down if it were not to downshift. Go with the newer vehicle, you should see overall better performance and fuel economy and I'd go newer with higher horsepower every time.

[moondoggiemn]

Good Day

"...the published info you already have." I did find a set of curves for each available engine in a booklet called "1992 Chevrolet Trucks". It's obviously a GM publication. My guess is someone scanned this one to pdf, which I downloaded. I've had no luck finding any others.

"...couldn't make up its mind what gear on the highway it wanted to be in..." I won't buy an automatic - it will be a 5 speed. Totally agree about the "hunting." It would be fun to re-write the software controlling the AT to eliminate this, but that's way beyond my capability.

"Go with the newer vehicle...." That's what I'll probably wind up doing. There are two problems with doing this, however. 1) I've seen almost no 1996-1998 4.3 5 speed trucks for sale; this led me to consider that 2) maybe the power characteristics at highway rpm (a 1992 5 speed with 3.42 gears would be turning ~ 1760 rpm @ 60 mph) aren't that much different. I had simply noticed that, as the power ratings went up, so did the rpm at which they occurred, which led me to question how much difference there was below 2000 rpm. If there's only 10 lb/ft of torque difference at 1760 rpm, I'd see essentially no difference in hill-pulling in 5th gear. This would allow me to consider 1988-1995 trucks too, of which there are a great deal more available to buy.

Why do I care? I'm 65 now & would like to have one vehicle that I actually want, as opposed to need; I've never had the financials to buy something I really wanted. I briefly had a 4.3 AT (4L60-E) & loved it, but hated the "hunting". I thought it would be fun to have one with a 5 speed. As long as I'm not lugging the engine, I'd just leave it in 5th up the slight freeway-type hills that make the AT hunt & let the speed drop some.

Yup - my request is kinda anal, but what can I say? That doesn't make me all bad, eh?

[ifixedit]

A couple of things.... If you want a manual transmission and the V-6, you might have better luck searching for a W/T (work truck) version, but then again why do you want the V-6 in the first place? My father in law has an 88 equipped with the 305 and a 5- speed, kinda rare but even there if you're open to a V-8 you may again have better luck finding that manual transmission you want. And, then you'll have even more power and probably as good on the mileage as well. Hard to fault the small block V-8 whereas it seems every V-6 of this vintage I've encountered ends up with head gasket issues, usually by 150,000 if not sooner, and if you've got one with more miles that hasn't had this issue you're on borrowed time.

[moondoggiemn]

Yup - most of the 4.3s are WTs, which is fine with me. I'm not having any trouble finding 4.3 V6 5 speeds, so that's not a problem. Again, I'm an old fart, & would kinda like to have one vehicle that I actually want; everything I've bought so far was to fill a need. As far as head gaskets: I'll test anything before I even make an offer - I have a Stant coolant system pressure tester. (My brother's a mechanic, & bought it for me, as he got tired of me borrowing his.) Yup - it could puke on the way home, but that's the way she goes. I'm pretty used to driving what others would consider junk. My wife's LeSabre is our "new" car - 140k; the Saturn I drive most of the time has 240k; my K3500 has 275k. I don't see any of these needing replacing anytime soon.

 

My plow truck (I live in northern MN), a 1988 K1500, rusted out from under me. I'm tired of fighting rust, so I'm going to buy a rust-free 1988-1999 K1500 4.3 V6 5 speed. Believe it or not, they do exist. I just passed up a 1998 that, from underneath, looked like it rolled off the line a month ago. By filling my need for a plow truck with what I want, I get two things. And, I'll NEVER drive it off my place during the winter.

 

Why not just put the plow on the K3500, you might ask? I might wind up doing that. I just think I'll have a lot of difficulty plowing with something that long (it's a crew cab).