Chevy 350 Swap Reliability??

Lil'John

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Are you asking reliable? Or 'functional'?

For reliable, any engine will last for 100s of thousands of miles with proper maintenance... some just last better with piss poor maintenance.

In my opinion, a warranty on an engine is a red herring argument. In my experience, an engine will fail darn near at the start or last way outside of warranty. So getting a 6 month junkyard warranty engine will be good enough to find out if the engine is good or not.

For functional, I wouldn't go carb even if I got the engine for free... ever. My home elevation is 3500'(outside Georgetown, CA). My work elevation is sea level(Sacramento). My wheeling elevation is 6000'+(Rubicon, Gold Lake, Fordyce). EFI allows for just drive and go. It also allows for 'consistent' adjustments.
 

matzell

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Look at the above post. A LS style engine looks cramped in the engine bay, while a SBC 350 looks at home to me. I am rebuilding a FJ40 now with a TBI 350 in it and a 6.0 LS that could go in it. I decided to keep the 350 for simplicity. Yes the LS can tell me what is wrong with it but the 350 is already there. Since you already have a 350 I would suggest just replacing it and everything else will bolt up. Put fuel injection on it and call it a day.
 
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350 conversions got a bad rap starting about 20 years ago as many were just cobbled together with fly by night conversion kits and companies. In the last 10 years or so, there have been a few reputable conversion vendors which have these swaps very reliable

My sell on the 350 is the gen I or II: That's because it is one of the most common engines in the world. Try getting a water pump or a belt for a inline 6 Toyota engine in nowhere USA. I was stuck in the San Luis Valley with a broken belt on my 350. There was NOTHING in the area. A farmer pulls up and says a NAPA store is about 3 miles away, would I like a ride? (This NAPA was in the middle of a row of silos, NO other stores) in about 20-30 miles.

They are easy to work on, parts are cheap and available everywhere

With LS engines having been around for 20 years now, Id bet you'd have just as easy of a time finding an LS3 serpentine belt in a small town NAPA as you would for an SBC. And both will be easier to find than any 40 year old 2F.
 
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You all have been a ton of help! There are a lot of insightful comments here. I think I will roll with a GEN1 350, and upgrade to the FiTech EFI with a command center sump. That seems like a reasonable, simple set up, that will work well in the ole FJ. It will be mated up to the OEM 4-speed. I’m curious about those of you that swapped in a 700r4 or TH350? Any issues or regrets? Or is it just a matter of preference? I see the benefits of an Auto when off-road, but more wisdom would be appreciated!
 

Lil'John

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Look at the above post. A LS style engine looks cramped in the engine bay, while a SBC 350 looks at home to me. I am rebuilding a FJ40 now with a TBI 350 in it and a 6.0 LS that could go in it. I decided to keep the 350 for simplicity. Yes the LS can tell me what is wrong with it but the 350 is already there. Since you already have a 350 I would suggest just replacing it and everything else will bolt up. Put fuel injection on it and call it a day.
Last I looked, an LS and an SBC are basically the same exact size. My notes show the LS being 1" narrower. Depending upon the intake on the LS, you can be even shorter in height than an SBC.

Aftermarket or cobbled EFI are the biggest 'breakers' of EFI issues. If you drop a stock EFI equipped engine in, the reliability is perfect... millions of cars don't like.

Yup, I've got two LSx swapped FJ55s. I daily drove my green one with a 6.0L engine. Perfect manners even with the 'dreaded' drive by wire.

The only 'cramping' I see in previous picture is a transmission cooler in the middle of the engine bay.
 

reddingcruiser

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Look at the above post. A LS style engine looks cramped in the engine bay, while a SBC 350 looks at home to me. I am rebuilding a FJ40 now with a TBI 350 in it and a 6.0 LS that could go in it. I decided to keep the 350 for simplicity. Yes the LS can tell me what is wrong with it but the 350 is already there. Since you already have a 350 I would suggest just replacing it and everything else will bolt up. Put fuel injection on it and call it a day.
Much of that is camera angle.

Just so we are comparing apples to apples:

The 5.3 is shorter than the 350 SBC by about 3/8", measured from the flex plate to the front of the water pump.

The 5.3 is 5 3/4" wider, measured at the outside edge of the valve cover. However, because of the cylinder head design of an LS, block-hugger header or Corvette LS manifolds (the two choices for an FJ40 swap) do not protrude much past the edge of the valve cover/coil packs. If you add headers or Ram horn manifolds to the 350, it virtually the same width.

Depending on the Plenum setup on the 5.3, and the Carb/air filter setup on an SBC, they are virtually the same height.

FWIW, I would not use the TH350. The last TH350 was manufactured in 1984. The 700R4 will give you O/D and save a few cents on gas.

These two pictures are the from the same position, with my 40 the 5.7 and the LM7
1903255
1903254
 

Lil'John

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It will be mated up to the OEM 4-speed. I’m curious about those of you that swapped in a 700r4 or TH350? Any issues or regrets? Or is it just a matter of preference? I see the benefits of an Auto when off-road, but more wisdom would be appreciated!
700r4? aka the exploder? No thanks. You can outspend your engine to beef them up.

I went from wheeling in an auto (86 s10 blazer with 700r4) to a 2F equipped FJ40 to a 5.0L TBI FJ40 with SM465. I found the manual to be more controllable.

With that said, my turbo 5.3L is getting a 4l80e transmission since I know it will be able to shift quicker to keep with the turbo.
 

NCFJ

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I'll chime in, and yeah I am a bit bias. That said, if you are going to do the work of replacing an engine and have the time and means to do it, I'd go with the LS based swap. Reliability, easy maintenance and gobs of HP and torque are the benefits. Drive ability will also be improved.

A stock 5.3L Vortec will give you around 320 HP at the crank, stock. More than enough for the task at hand. It'll give you great off throttle response at any angle you'll put your truck and it won't give you a hard time just because you changed elevation. Parts and a wrench that can work on them can be found everywhere USA. Simply put, it's the SBC your Grandfather dreamed of, why use your Grandfather's SBC? :)

One man's OPINION
 
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I had a 350 ramjet crate in my fj60 and the thing never skipped a beat. Po drove it from california up to sudbury in northern ontario Canada and 9 years later when I sold it the new owner drove it from sudbury to olkahoma again without issue.

That thing had all the power in the world and would spin 40" tires on dry rocks with ease then get you home at highway speeds without breaking a sweat.

That being said, I would consider a low mile junkyard ls if I were in your position.

D
 
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I'll chime in, and yeah I am a bit bias. That said, if you are going to do the work of replacing an engine and have the time and means to do it, I'd go with the LS based swap. Reliability, easy maintenance and gobs of HP and torque are the benefits. Drive ability will also be improved.

A stock 5.3L Vortec will give you around 320 HP at the crank, stock. More than enough for the task at hand. It'll give you great off throttle response at any angle you'll put your truck and it won't give you a hard time just because you changed elevation. Parts and a wrench that can work on them can be found everywhere USA. Simply put, it's the SBC your Grandfather dreamed of, why use your Grandfather's SBC? :)

One man's OPINION
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I hear what you all are saying. I’d consider a 5.3 swap, but I’m worried I’d be out of my depth with the addition wiring and fabrication required. Also, the 5.3’s are much more costly and wont appear to line up with my existing exhaust/headers. I need to stay budget minded, as this is just a hobby/toy, and my wife will only bend so far, haha...
 
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