Trying to help a friend with motor selction for his cj5. He currently has a carb'd 4.3 and options are a vortec 4.3 or possibly a 4.8. The 4.3 would be the easiest but that motor has become more difficult to find as a low mileage unit. Any opinions? We're not looking for any more motor than that. He has built d44's and 35's and it is staying that way. Power is not the problem, but smooth running and re-starting at angles is what we're looking to gain.

I thought it was pretty easy to do a TBI swap on those motors?

Trying to help a friend with motor selction for his cj5. He currently has a carb'd 4.3 and options are a vortec 4.3 or possibly a 4.8. The 4.3 would be the easiest but that motor has become more difficult to find as a low mileage unit. Any opinions? We're not looking for any more motor than that. He has built d44's and 35's and it is staying that way. Power is not the problem, but smooth running and re-starting at angles is what we're looking to gain.
4.8 by far! 300HP V8 power stock! Shit load of aftermarket parts. I think the 4.8L is the dark horse of Gen III motors, cause everyone wants a 5.3L.

I have seen used 100k mile 4.8ls for 300 bucks! Cause no one wants them. Also a swapping to a 6.0L later is a bolt in longblock swap and tune!!!

The shitting thing with the Vortec 4.3L is CPI injection, intake water leaks, and 200hp!

i would have to agree. Probably could do the 4.8 as cheap or maybe even a little cheaper from scratch than a 4.3. I have a 4.8 with nothing more than a mild tune I did myself with hptuner stuff and it has plenty of power for what it is. I have less than 1000 bucks in my complete setup too. The intake issues with the 4.3 would be a draw back for me. Zero aftermarket support if you ever want to make a little more power with it, unless you find a marine intake for it and they are usually pricey. Plus a stock 4.8 makes better power than a warmed up 4.3.

I thought it was pretty easy to do a TBI swap on those motors?

Having done a tbi conversion on my smallblock, I would never recommend it. It was far more temperamental than my quadrajet. I'm looking for a factory fuel injection system with a MAF for reliability.

Again, power is not what we're after. It would truley be unfortunate to take a rig that's reliable, throw more power at it and start having problems (been down that road with my rig). What was the last year the 4.3 was made?

Having done a tbi conversion on my smallblock, I would never recommend it. It was far more temperamental than my quadrajet. I'm looking for a factory fuel injection system with a MAF for reliability.



Are you talking about your old Pro-jection? Because there is a big difference between the factory TBI and Holley's lame attempt.

Is the 4.3 longblock in John's truck stock?

Wilson, I wonder what went wrong. I have had tons of TBI, and not a one of them has ever given me any issues as far as running smooth goes-- when relevant sensors fail, you get some issues but they're pretty easy to ferret out. :confused: I really couldn't be happier with TBI.

ProJection, not so much. :D

I know you really like the multipoint stuff but for what its worth, here's my suggestion

Intake
http://www.summitracing.com/parts/EDL-3713/?rtype=10

Injection
http://www.affordable-fuel-injection.com/index.php?id=24&title=Chevy+Throttle+Body+Fuel+Injection

No motor swap, minimal down time

Are you talking about your old Pro-jection? Because there is a big difference between the factory TBI and Holley's lame attempt.

Is the 4.3 longblock in John's truck stock?

No, I won't even bother mentioning projection...everyone knows it's a joke (at least they should). Yes, the longblock is stock and is low mileage. can vortec top end stuff bolt right onto an older block? It would be a very good candidate for tbi if it wasn't for my aversion to it.

Wilson, I wonder what went wrong. I have had tons of TBI, and not a one of them has ever given me any issues as far as running smooth goes-- when relevant sensors fail, you get some issues but they're pretty easy to ferret out. :confused: I really couldn't be happier with TBI.

ProJection, not so much. :D

It was a setup from AFI. After 4 proms, a ruined set of headers, 5 trips with major issues, and over 20 frustrated email exchanges it ran decently and then started having phantom sensor failures and became generally unreliable. I could load it on teh trailer, and when I went to unload it, fuel would be pouring out of my collector gaskets (really happened once) Things really went bad when I put larger heads on. For a bone stock motor it may work all right, but it is very rudimentary. Now after having a system with a maf that can adapt on the fly to huge changes in altitude, and other paramteters that a tbi system couldn't even possibly factor for, I would never try it again.


We do know tbi is the easy answer for this project, but we want to weigh out better options before going with what's "easy."

I completely forgot your trials with AFI.

I vote 4.8 LS before 4.3 vortec. The stock motor will be more than enough for now, and when he wants to upgrade he'll have an ever increasing LS series aftermarket to source from.

He does have a SM465 right? There's some good info on the swap here:
http://www.pirate4x4.com/forum/showthread.php?t=863783

I completely forgot your trials with AFI.

I vote 4.8 LS before 4.3 vortec. The stock motor will be more than enough for now, and when he wants to upgrade he'll have an ever increasing LS series aftermarket to source from.

He does have a SM465 right? There's some good info on the swap here:
http://www.pirate4x4.com/forum/showthread.php?t=863783

He's running a np435 to a super 18, LOL. You've seen his rig so you will understand that aside from this motor swap and some deeper gearing it is as built as it will get. It's a nice little jeep that does everything (but the hammers) with ease, not that he had any major issues on any of the trails we ran. When he wants to try and eat my dust, he'll build another rig.

http://i225.photobucket.com/albums/dd26/rockbuggyguy/KOH%202010%

Having done a tbi conversion on my smallblock, I would never recommend it. It was far more temperamental than my quadrajet. I'm looking for a factory fuel injection system with a MAF for reliability.

Again, power is not what we're after. It would truley be unfortunate to take a rig that's reliable, throw more power at it and start having problems (been down that road with my rig). What was the last year the 4.3 was made?

I believe the last year the 4.3 was made was around 2004 unless the were still putting them in the 1500's for the v-6 option. I know they were used in the s-series up until they stopped making them. Personally id recommend the 4.3 as i've had many of these motors and the have always been reliable. The 4.3 is going to be lights than the 4.8 although probly not by a whole lot. you should have a wide variety of parts available as the 4.3 came in a wide variety of vehicles.

Glad to here they were around into the early 2000's, I wasn't sure and we'd like to find as low mileage as we can. Swapping in a 100+k motor doesn't make much sense, which is where the 4.8 idea came from.

I believe the last year the 4.3 was made was around 2004 unless the were still putting them in the 1500's for the v-6 option. I know they were used in the s-series up until they stopped making them. Personally id recommend the 4.3 as i've had many of these motors and the have always been reliable. The 4.3 is going to be lights than the 4.8 although probly not by a whole lot. you should have a wide variety of parts available as the 4.3 came in a wide variety of vehicles.The 4.3L is still available in the current 2010 1500 trucks. The new ones have distrbutoless coil pack ignition, DBW, and use LS PCM. But they still have the CPI injection which sucks.

http://archives.media.gm.com/us/powertrain/en/product_services/2010/gmna/Photo%20Library/Gen1eV6/2010%204.3L%20V6%20LU3%20SLV%20LoR.jpg


A 4.8L 100k mile motor is fine I seen these motors run 200k plus easy!!!. I wouldn't be scared of a 100k Gen III.

Does the 4.8 suffer the same oiling problems as the other LSX engines? Glad to hear they can be found....time to make some calls.

I think the 4.8 would be much better choice there a fun moter to drive.

I have had to replace two 4.3l vortex and it is hard to find one that even runs let alone low miles. From my luck with 4.3s i would say they are a terd moter and may explode randomly and any moment.

But that is just my expiriance with themthey seem to be pretty popular i not sure why.

http://i225.photobucket.com/albums/dd26/rockbuggyguy/KOH%202010%

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http://i225.photobucket.com/albums/dd26/rockbuggyguy/KOH%202010%20Wheeling/KOH2010shakey241.jpg

Does the 4.8 suffer the same oiling problems as the other LSX engines? Glad to hear they can be found....time to make some calls.What oiling problems????

The 4.3L is subject to the same problems are the Vortec 350. Intake leaks coolant into oil, spun rod bearings, and injector clogging!

And the MPG will be better with the 4.8l!

What oiling problems????

The 4.3L is subject to the same problems are the Vortec 350. Intake leaks coolant into oil, spun rod bearings, and injector clogging!

And the MPG will be better with the 4.8l!

I hear about lots of oiling issues, custom pans and spun bearings on fresh motors with the 6.0.

I hear about lots of oiling issues, custom pans and spun bearings on fresh motors with the 6.0.Ah, most times its from using the improper oil pump to pick-up o-ring. I fault human error vs the engine.

Ah, most times its from using the improper oil pump to pick-up o-ring. I fault human error vs the engine.

I would have to agree. Our fleet has had a few dozen of these motors with over 200k. All our 4.8/6.0 (i don't think we have any 5.3's) engine failures were caused by human error.

4.8's have 300 hp stock?? Hmmm I may have to swap out my 4.3L when it goes boom.

I have a 93 4.3L CPI and literally run it on like 6 wires. Very easy to hook up, but you probably know that.

4.8's have 300 hp stock?? Hmmm I may have to swap out my 4.3L when it goes boom.

I have a 93 4.3L CPI and literally run it on like 6 wires. Very easy to hook up, but you probably know that.

302HP@5600 and 305 Lbft@4600. Torque is low cause its a short stroke motor.
http://archives.media.gm.com/us/powertrain/en/product_services/2010/gmna/HPT%20Library/Gen%20IV/Gen%20IV%20Truck/2010_Vortec_48L_L20_Silverado.pdf

What about the non VVT 4.8's? He's interested in the 4.8 if we can fit it, obviously a 4.3 will be damn near bolt-in.

I got nothing except Ive never seen any issues with a 4.3. Ive got no experience with a 4.8

I suggest a poll.

What about the non VVT 4.8's? He's interested in the 4.8 if we can fit it, obviously a 4.3 will be damn near bolt-in.

Sorry the link is for the 2010 motors!!! Nice catch! GM added VVT for the 4.8L and 5.3L's this year. Really flattens out the torque curve.

The 2006 down are Gen III motors and non VVT etc...

The 2003 up will be DBW with some van 4.8L being DBC till as late as 06.

Measure it and compare to this
http://img186.imageshack.us/img186/4810/truckjb4.gif