ENGINE SWAP -or- SELL! the final say for the most efficient square body motor!

mr heavy-chevy

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I have been crunching the numbers and driving my square body every day for the last year.... after all this time of getting 12-14 MPG i have decided that i either need a more efficient motor, or, a more efficient vehicle.......

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even with a 4.3 V6 and a 700R4 overdrive

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after doing much research, the most popular engine swaps for these trucks are as follows:

5.7 SBC TBI with roller cam
5.3 LS chevy
5.9 CUMMINS 12-valve diesel
3.9 CUMMINS 4BT diesel

transmissions are irrelevant. we all know a stick-shift will free up more HP than an automatic but some people will go heavy duty, turbo 400, 700R4 or even full wiring harness 4L60.
im going to ignore transmissions and focus on engines and gas mileage.

5.7 SBC TBI with roller cam lucky to average 15
5.3 LS chevy lucky to average 17
5.9 CUMMINS diesel unable to find concrete data
3.9 CUMMINS diesel unable to find concrete data

some people say the cummins will get 25mpg solid.... but with turbos and modifications, who knows.


any one of these motors will cost about $3,000 - $5,000 in parts alone. labor rates these days are astronomical.

Not having a new car payment, with cheap insurance, usually, equals out to having something good on gas but expensive payments/insurance.

im considering the diesel swap to save my truck.

i need concrete feedback on what setup will yield at least 20MPG in my daily driver, or else im going to have to give up and sell the truck off =(

so lets have a discussion on who has done this swap and actually seen the numbers:gathering:
or shoot me an offer on the truck.
i love it to pieces, but its just too thirsty. :sorry:
 

Geektrucker

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I have been crunching the numbers and driving my square body every day for the last year.... after all this time of getting 12-14 MPG i have decided that i either need a more efficient motor, or, a more efficient vehicle.......

You must be registered for see images


even with a 4.3 V6 and a 700R4 overdrive

You must be registered for see images


after doing much research, the most popular engine swaps for these trucks are as follows:

5.7 SBC TBI with roller cam
5.3 LS chevy
5.9 CUMMINS 12-valve diesel
3.9 CUMMINS 4BT diesel

transmissions are irrelevant. we all know a stick-shift will free up more HP than an automatic but some people will go heavy duty, turbo 400, 700R4 or even full wiring harness 4L60.
im going to ignore transmissions and focus on engines and gas mileage.

5.7 SBC TBI with roller cam lucky to average 15
5.3 LS chevy lucky to average 17
5.9 CUMMINS diesel unable to find concrete data
3.9 CUMMINS diesel unable to find concrete data

some people say the cummins will get 25mpg solid.... but with turbos and modifications, who knows.


any one of these motors will cost about $3,000 - $5,000 in parts alone. labor rates these days are astronomical.

Not having a new car payment, with cheap insurance, usually, equals out to having something good on gas but expensive payments/insurance.

im considering the diesel swap to save my truck.

i need concrete feedback on what setup will yield at least 20MPG in my daily driver, or else im going to have to give up and sell the truck off =(

so lets have a discussion on who has done this swap and actually seen the numbers:gathering:
or shoot me an offer on the truck.
i love it to pieces, but its just too thirsty. :sorry:
You forgot an engine... Inline 6 250... I'll just leave this here...
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Sent from the back-woods of Maine, via cah, beah, and lobstah bub! Pine trees MAY have been harmed in the making of this post.
 

CSFJ

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You forgot an engine... Inline 6 250... I'll just leave this here...
You must be registered for see images attach


Sent from the back-woods of Maine, via cah, beah, and lobstah bub! Pine trees MAY have been harmed in the making of this post.

He's running a 4x4 though.

Any of the Cummins option will require swapping in a different trans, so factor that into cost also. Another thing to consider, is how long will it take for the investment to pay off? Myself, I have a little 5 speed Saturn for the daily grind to work and back, and save the trucks for the weekends.
 

Georgeb

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He's running a 4x4 though.

Any of the Cummins option will require swapping in a different trans, so factor that into cost also. Another thing to consider, is how long will it take for the investment to pay off? Myself, I have a little 5 speed Saturn for the daily grind to work and back, and save the trucks for the weekends.

I also ran a saturn as a commuter car. I figured it saved me about $100 a month when gas was around $4 gal. Friday was my "Take your square to work" day. Still miss my lil car.
 

1987 GMC Jimmy

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I know it wouldn't be the most powerful, but you could do a turbo 6.2. They can get in the twenties.
 

rich weyand

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OK, let's say you switched engines and got 20 miles per gallon, which you won't.

100,000 miles would be (round numbers) 5000 gallons instead of 8000 gallons. At $2.50 per gallon, that's a difference of $7500 over 100,000 miles.

You basically come out even, assuming you can get up to 20 miles per gallon and drive the truck another 100,000 miles. If you can't get the mpg that high, or don't get 100,000 miles, you are money out of pocket on the change.
 

mr heavy-chevy

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OK, let's say you switched engines and got 20 miles per gallon, which you won't.

100,000 miles would be (round numbers) 5000 gallons instead of 8000 gallons. At $2.50 per gallon, that's a difference of $7500 over 100,000 miles.

You basically come out even, assuming you can get up to 20 miles per gallon and drive the truck another 100,000 miles. If you can't get the mpg that high, or don't get 100,000 miles, you are money out of pocket on the change.


that is a very good point... thank you.

it kind of circles back to the whole "NEW gas sipping car, high payment & insurance & registration... or... cheap insurance, registration, no payment, just thirsty"

most americans spend $300 a month on gas (average)

even im not that bad.:shrug:


side note
the 250 is an awesome motor.
i had one in my 1970 chevelle. it got 15-17 MPG with a powerglide transmission LOL
 

CSFJ

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Doesn't have to be new to be reliable. The Saturn I'm running, is a 2001 model, with 300k on the body. I lucked into one the spent it's life in California and Washington state until 2014. So it's rust free. It ran fine with 300k on the engine, just used a little oil, but I had the opportunity to go completely through the engine and trans, so I have no doubt it will go another 300k. I average between 29 to 32mpg on the 75 mile round trip to work and back every day. Probably only use about $150 a month to run it. The bonus part is that the salvage yards are full of these things, so spare parts are plentiful, and they're incredibly simple to work on.
 

Camar068

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Doesn't have to be new to be reliable. The Saturn I'm running, is a 2001 model, with 300k on the body. I lucked into one the spent it's life in California and Washington state until 2014. So it's rust free. It ran fine with 300k on the engine, just used a little oil, but I had the opportunity to go completely through the engine and trans, so I have no doubt it will go another 300k. I average between 29 to 32mpg on the 75 mile round trip to work and back every day. Probably only use about $150 a month to run it. The bonus part is that the salvage yards are full of these things, so spare parts are plentiful, and they're incredibly simple to work on.

is that one of those Saturns they had a recall on and would replace the engine for you free? My sister bought one with a bad motor for $1500 knowing this and flipped it and made $3,000 in a week lol.
 

CSFJ

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Nope. 2001 SW2 wagon. From when Saturn wasn't a rebadged Opel platform.
 

Rusty Nail

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I've been shopping for specifically a 1996 RS Camaro with the RPO Y87.

I have driven a 2001 Bonneville SLE quite a bit and with 180k on the odo, it gets 30 mpg highway.
The world's flattest torque curve.
I love a 3800 series 2, but only because it's one of the greatest motors ever. I used to dream about swapping one into my GMT400. Problem is, the engine casting is FWD. HOWEVER! GM built a RWD 3800 for 96-02? and put it in fourth gen F bodies. camaro/firebird (Different engine casting) A variation of the L67 called the L36 -That's what you want!

I've done the homework.

Omg hot. 240 horse, 280 torque.... (supercharged) N/A motors are packin 180/240 your truck didn't make that new.
I feen for this in RWD, and have picked a Camaro to lower one inch and daily. Now all I gotta do is find one!

You could swap that in a square. EASY.....and have overdrive. Buy it salvage and pay next to nothing.

Nobody wants that, but it is certainly in MY future and I bet it would smoke the **** out of a 4.3. AND pull better MPG !!!!! SUPER CHEAP. I'm sure I could find plenty of V8s to embarrass and look forward to it.

I'd prolly want the whole car for plug n play powaaahhh! (and you could get the seats!)
 
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wndwlkr65

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Just buy a Dodge Ram cummins, good fuel mileage & power to pull a house!
 

Geektrucker

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I've been shopping for specifically a 1996 RS Camaro with the RPO Y87.

I have driven a 2001 Bonneville SLE quite a bit and with 180k on the odo, it gets 30 mpg highway.
The world's flattest torque curve.
I love a 3800 series 2, but only because it's one of the greatest motors ever. I used to dream about swapping one into my GMT400. Problem is, the engine casting is FWD. HOWEVER! GM built a RWD 3800 for 96-02? and put it in fourth gen F bodies. camaro/firebird (Different engine casting) A variation of the L67 called the L36 -That's what you want!

I've done the homework.

Omg hot. 240 horse, 280 torque.... (supercharged) N/A motors are packin 180/240 your truck didn't make that new.
I feen for this in RWD, and have picked a Camaro to lower one inch and daily. Now all I gotta do is find one!

You could swap that in a square. EASY.....and have overdrive. Buy it salvage and pay next to nothing.

Nobody wants that, but it is certainly in MY future and I bet it would smoke the **** out of a 4.3. AND pull better MPG !!!!! SUPER CHEAP. I'm sure I could find plenty of V8s to embarrass and look forward to it.

I'd prolly want the whole car for plug n play powaaahhh! (and you could get the seats!)


I VERY much want to see someone do a 3800 SC2 swap in a square..oh and by the way... a few places make a bell housing adapter for it ...just saying.
http://www.transmissionadapters.com/GM%203800%20series.htm

I've also thought seriously about taking the whole front cradle from a GTP or Regal and flipping it into the bed for some serious weight redistribution...

The biggest downside to a SC2 swap is having to run premium only...not that I've researched it or anything...
 

Rusty Nail

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The Camaro engines made 200 horsepower!
Efffff.....

Right now I average 22.2 mpg in the Bonneville and my driving is "spirited". 67 mph on the highway. @65 I average 22.3!

I see some people find issue with the blown engines in SOME swaps , because the throttle body points towards the firewall. Can't change it.
The F body heads are different than the supercharger heads, because intake manifold.
Yeah, you're told to run premium with a blower, but I would go N/A.
A fella would have to pick one or the other starting out.

I've personally seen a GTP motor in an 80's G-body and it made my dick hard. I've seen it done in a GMT 400 and it looked at home.

A square has even more wiggle room and there is no question the motor makes enough power even N/A.

So why doesn't anybody make one?

Is it not cool or something?

The highest gear ratio available for an SLE Bonneville in 2001 was 3.08 and that's what I drive with. It's quick no doubt, but the thought of 3.73s or even better is mind boggling!

You'd snap your ****** neck!

Is that why nobody does it?
The last guy that tried it died ?

Don't find it on the Internets , what are we missing?
If you can put one in a 1985 MONTE CARLO, you can put it in ANYTHING!

I mean seriously, come on. A vortex "ls" swap is ALREADY more tired and played out than black wheels. People spend THOUSANDS swapping in a $200 or $300 motor only to have it blow up and NOBODY ever questions why you can pick them up for next to nothing and junkyards are full of them? It's only 10 years old!
Really NOBODY EVER says "hay wait a minute, I can make double this power for half as much if I spent it in my original motor!"

?

It's just me I guess. Enjoy your LEDs and 40 series trail grapples. I hope those blue lights help you see the curb really good because if you hit one, you're really screwed! Have you even paid for those wheels yet?
Just like lowridin on 13s back in the day except we weren't POSERS.
It's ALLL hype , like obamacare. Trendy, fake ******** with zero sex appeal. I could not care less!

Like watching some dudes in this MSB fix up a truck , it's great to watch and then?
The dreaded LS swap. :( Aww ****! Just when it was gettin good.
Never mind !

I think that is the newest best way to ruin a truck and destroy value.
I guess MAYBE if they were as great as everyone seems to think they are, I'd feel differently. BUT I wouldn't.

Fabbed up motor mounts I guess, hadn't really considered that but how bad could it be?
http://www.hotrodders.com/forum/l67...uestions-229504.html#/topics/229504?_k=3wuipu

I've got a good line on F-body parts, all I'd have to do is ask.

Well, and pay... but I bet it's CHEAP.
 
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