Help me decide... 383 or LSx?

[L31MaxExpress]

I voted to keep the 3500 until it dies. There is a gentlemen on the forum that goes by L29sub that ran an NV3500 behind a lightly massaged 454 with a carb in his k2500 Suburban and it did fine, evening for towing. Though he did admit it was the weakest link in the drivetrain. He liked the smoothness of the 3500 over the more truck like shifting 4500.

The fuel injection options would be the only reason to jump to an LS style motor in my opinion. I actually have a Vortec 7400 so I already have 8 independent injectors so no real reason to LS swap my truck once I finish the 0411 swap. Only two crazy options are in my mind; if the cam fails but the motor is salvageable I'll throw in a bigger cam and injectors and maybe eventually some forced induction or if the cam kills the block I might go to a Duramax and try and find the elusive ZF6 that bolts up to it.

With that said, I think the ZF6 that bolts to the 8.1 Vortec also bolts to the Duramax and may even bolt up to the smaller LS variants since GM autos seem to cross between big blocks and small blocks pretty easily (4l80 swaps into 4l60 trucks come to mind). That is just a naive/hopefully ASSumption on my part though, still worth some research though.

I kick myself for not buying the ZF6 that got offered to me for $1200 with a gear vendors behind it. Was out of a 6.0L truck. Yes it was a ZF6 not sure why it was in a 6.0L truck. Maybe the truck had an 8.1 to start with and had been downgraded to the 6.0L or was a NV4500 truck upgraded to the ZF6.

 

[b454rat]

I don't own an LS, but bunch of buddies have em. Granted they are in stock form, and I'm not impressed at all. One buddy tows a lot, has had small and big block trucks, now has a 6.0. The small block didn't do as well as the 6.0, but did good. The big block was awesome, and got better gas mileage, empty or loaded. I'm tempted to get a newer truck with an LS, the state has auctions n they sell reasonably priced. And not always beat to ****, many are supervisors trucks, and they are detuned so nothing breaks and knowing the state, try to get better fuel economy. But in actuality prolly gets worse cause foots into it more....

 

[b454rat]

But I think if you get a newer motor with the 6L or 8L or whatever they are it would be better. I have an 08 Tundra with the 5.7, 370 horse and 380 torque. Even lifted with 35s and 4.30 gears, it pulls hard in every gear. Seems like it shifts 4 times before crossing an intersection. But I've been told that the newer trannies have to go with newer motors. I wanted one for my Yukon when the 406/Ramjet/whipple is in, but said its a wiring and tuning nitemare.

 

[97silveradoguy]

Does the distributor mainshaft wobble? I'm told the plastic distributors are bad for wearing the bushings that stabilize the shaft.

That might account for the broken carbon button.

That is the main cause of the P0300 random misfire code. The plastic distributor is junk.

 

[langkg]

383 with Holley Sniper and Hyperspark. Plug and chug, fairly inexpensive and will provide plenty of power without having to re-engineer the whole truck or have it look like an abortion.

 

[dmhscorpion]

I installed a GM factory HT383E https://www.chevrolet.com/performance-parts/crate-engines/small-block-engine/ht-383e in my 1999 Tahoe 4X4 2 door at 300K miles. It came with a a 24-month or 50,000-mile/80,000-kilometer GM limited warranty. I am real happy with it. It comes with the flex plate, water pump, distributor, cap, wires and plugs installed, it was a direct swap. i have yet to have it tuned, but even with the stock ECM, it is a huge difference in power.

 

[stutaeng]

Another advantage on LS compared to SBC is that LS tend to leak less.

LS are supposed to be tighter sealed all around.

Not sure if that matters to anyone.

 

[PlayingWithTBI]

LS are supposed to be tighter sealed all around.

I don't know, my 88 5.7 doesn't burn or leak a drop, other than my PCV valve grommet in an aluminum valve cover, which I just fixed today (hopefully). The old 2-piece rear main gaskets had a habit of leaking but not anymore with proper installation.

 

[b454rat]

I had an 89 with 235K I think on it before I pulled it for the 406. Never marked it's territory......

 

[AK49BWL]

Mine doesn't leak anything either...which is more than I can say for my Blazer's rebuilt 4.3 lol