1989 Suburban with 5.3LS/700R4

[Firebirdjones]

Interesting swap. I'm a 6.0 fan myself but that 5.3 should work nice for you. Too bad they didn't swap in a 60E instead of that 700, then you would have total control of both the engine and trans with simple key strokes
It will take alot of trial and error on the 700 to get the shift points in a happy spot for that 5.3.

If you had HPtuners I could send you a stock 5.3 tune file so you could flash that in to start with. I can tell you though they need alot of time tuning and tweaking to optimize even a stock engine.

Neat truck, and a good deal considering the coin it takes to do an LS swap and do it right. You'll have some fun with that.

[2ndGenRR]

Originally Posted by Edahall

The 10 bolts should hold up fine but anything can be broke by someone who tries hard enough. However, lower ratio gear sets are inherently weaker than the higher ratio gear sets. Where it would get you is if you into heavy pulling.

Have you noticed any fuel economy differences with the change?

No heavy pulling with this 'burb, I use my '06 3/4 ton 'burb for pulling. Haven't run enough fuel through it yet to notice a fuel economy change, but I have to believe it's going to be better without all the downshifting. I'm buzzing down the highway at 70 and only running 2200-2300rpm.

[2ndGenRR]

Firebirdjones - Yeah, the 6.0L would be more fun, but now that an LS engine has been swapped into this truck I can always swap to another LS at some point or even go with a power adder of some sort.

For this summer, I'm just going to drive the wheels off it and see which direction I want to go from there.

[Firebirdjones]

Originally Posted by 2ndGenRR

Firebirdjones - Yeah, the 6.0L would be more fun, but now that an LS engine has been swapped into this truck I can always swap to another LS at some point or even go with a power adder of some sort.

For this summer, I'm just going to drive the wheels off it and see which direction I want to go from there.

Very true, now that the hard work is done, another swap is cake.

Like you mentioned, I'd enjoy it as is for a while. There is alot to be found in the tune on these things. Those little 5.3's are pretty snappy for their size, and a stock tune leaves about 20-25 hp on the table. That might be enough to persuade you to keep it.

[Edahall]

Originally Posted by Firebirdjones

Very true, now that the hard work is done, another swap is cake.

Like you mentioned, I'd enjoy it as is for a while. There is alot to be found in the tune on these things. Those little 5.3's are pretty snappy for their size, and a stock tune leaves about 20-25 hp on the table. That might be enough to persuade you to keep it.

You could also bolt on a supercharger for a lot more power.

[2ndGenRR]

Originally Posted by Edahall

You could also bolt on a supercharger for a lot more power.

I was thinking STS rear-mounted turbo...see how fast I can find the limits of that 700r4!

[Firebirdjones]

Originally Posted by Edahall

You could also bolt on a supercharger for a lot more power.

Yep, I have a maggie sitting here for the 6.0.

[Firebirdjones]

Originally Posted by 2ndGenRR

I was thinking STS rear-mounted turbo...see how fast I can find the limits of that 700r4!

[justpball]

Very nice truck bro!
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[2ndGenRR]

Originally Posted by justpball

Very nice truck bro!
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Thanks justpball - Your truck is way sweet...saw that you bodydropped it earlier this year...lots of work going low!

[justpball]

Thanks! It is a lot of work... LOL
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[2ndGenRR]

Hey Guys - thought it was time to drop an update.

So, one afternoon my buddy and I decide to head to another buddies house and drag up the sandhill at the back of his property. Had a great time and I actually beat his big-block K20 a couple of times. Afterwards we sit around enjoying a few barley pops until it's time to head home. The wives of course, don't want us driving because of the barley pops (yes, they are smarter than us), so we load up with the wives at the wheel. They decide to drag up the hill...my wife wins and also pops the head gasket on my 5.3 while standing on the rev limiter...doh!

That's the bad news...the good news is that she feels really bad about it and I get the green light to spend some dough on a new engine, because you know those head gaskets are really hard to fix...

I was looking for a 6.0 until I called the local speed shop and they happen to have a 5.3 that has already had all the good upgrades and dyno tested at 450hp. They made me a good deal on it, so I dropped the 'burb off at their shop and they are swapping the engine for free in exchange for me showing the 'burb in their booth at the Metro Cruise in August (the Grand Rapids version of the Woodward Dream Cruise).

I'm really looking forward to getting it back, but I'm going to have to take it easy with the 10-bolts and 700r4. Should be a bunch of fun at the Silver Lake Sand Dunes as long as I roll into the gas...

[68Timber]

Congrats on the wifey participating in the hobby, some of us only wish!

[2ndGenRR]

Originally Posted by BRUISER

Congrats on the wifey participating in the hobby, some of us only wish!

You have no idea...she's a total speed demon. She doesn't like my '50 Chevy Sedan because it's too slow!

[turbo350]

Sounds like a fun truck. Curious what were you getting for fuel mileage on the freeway with your set-up.

[2ndGenRR]

Originally Posted by turbo350

Sounds like a fun truck. Curious what were you getting for fuel mileage on the freeway with your set-up.

I don't know...never got the chance to check it after the gear swap. Prior owner claimed he was getting close to 20mpg...which I'm skeptical about. I would guess closer to 16-17mpg.

[Firebirdjones]

I'd bet the previous owner wasn't kidding on the fuel mileage, considering this is a larger burb.

I installed a 6.0 in my blazer with a 4L60 and it routinely gets 17 mpg city and 22 mpg highway with 3.73's and 33" tires.

[Edahall]

Originally Posted by 2ndGenRR

I don't know...never got the chance to check it after the gear swap. Prior owner claimed he was getting close to 20mpg...which I'm skeptical about. I would guess closer to 16-17mpg.

That 20 mpg figure would easily be possible at 55 mph. After between 60-65 mph, these boxy trucks start to really suck fuel. On my old 1982 Suburban with the 6.2 diesel, I would lose 9 mpg driving 75 mph vs 60 mph.

[WarBeard]

Lockers IMO are what kills the ten bolt in offroad situations. If you have an open diff then you should be ok. Your front ten bolt (Going by the year) will be a 30 spline wich is the strongest of the ten bolts. I run 37''s on my 30 spline 10 bolt and all I ever brake is the U-joint I have never actually broken the axle itself. You can still drive home on this.

[Firebirdjones]

Originally Posted by Edahall

That 20 mpg figure would easily be possible at 55 mph. After between 60-65 mph, these boxy trucks start to really suck fuel. On my old 1982 Suburban with the 6.2 diesel, I would lose 9 mpg driving 75 mph vs 60 mph.

I cruise at 70 mph to get those figures I posted with my 6.0 in my 72 blazer 4x4. The 4L60 overdrive keeps the rpms reasonable even with 3.73's.

My 79 1 ton pickup with a 502/400 turbo and 3.73's gets 14 mpg if I keep it at 65 mph (about 2800 rpms). With the gear vendor going in I should pick up another 2-3 mpg

It's all in the tune...