Thinking about engine choices (POLL)

Best all around fuel economy and power for 1k budget

  • 3800 Series II from an fbody

    Votes: 5 21.7%
  • Hopped up 4BT Cummins

    Votes: 3 13.0%
  • Ecotec 4cyl

    Votes: 0 0.0%
  • Vortec 350

    Votes: 11 47.8%
  • 6.2/6.5 Detroit Diesel V8

    Votes: 3 13.0%
  • Chevy 4.3 V6

    Votes: 1 4.3%

  • Total voters
    23
Status
Not open for further replies.

dream on mcss

G-Body Guru
Jun 22, 2011
617
2
0
Oxford, MI
Hey y'all. Got a question and I wanted to see what ideas you guys would have about engine choices for me. Anyways, next month I should be getting that cutlass that I was blabbing about awhile ago lol, and I've been thinking about what I want to put under the hood. Its a 1978 supreme with only 77k original miles, with the 260 v8 and three speed auto, thats gotta go. Since gas is crazy expensive (diesel even higher) and I'll be needing something fuel efficient to go back and forth from Ohio to Michigan every weekend for college. I want something that still has decent power with somewhat good fuel economy. Something with a baseline of atleast 200hp and could get atleast 17mpg. No, I dont have enough money for an LS swap, although that would be amazing, I need something that'll fit into a budget of around a grand. Now, call me crazy, but I'm honestly thinking about a 4BT Cummins swap. I'm pretty knowledgeable when it comes to diesel engines, and I could do a few things to hop one up a bit (makes 105hp stock, good torque though) but the main thing is that realistically with a manual trans that combo could probably get 25mpg EASY, and with a few simple mods to the injection pump and I could easily have another 50hp. I was thinking either that or a turbo'ed series 2 3800. What do you guys think?

*I edited the poll based on everyone's opinions, so don't forget to re-vote, lol.
 

Kansas Bu Wagon

G-Body Guru
Jul 9, 2012
500
15
18
Wichita, Ks
I don't see a cummins swap being any cheaper than an LS swap, or the 3800 for that matter.

4.8's and 5.3's are cheap.

But a 4BT would be the coolest of your choices.
 

dream on mcss

G-Body Guru
Jun 22, 2011
617
2
0
Oxford, MI
Kansas Bu Wagon said:
I don't see a cummins swap being any cheaper than an LS swap, or the 3800 for that matter.

4.8's and 5.3's are cheap.

But a 4BT would be the coolest of your choices.

Thats what I'm saying. I know it wouldn't be the cheapest but come on with all the performance parts for the 6BT out there why not. And it would probably be one of the easier swaps being that its all mechanical. The only hard part would be fabbing mounts and finding a transmission to bolt up behind it. From there on out it wouldn't be hard at all, am I wrong?

And this right here is why I want a cummins: https://www.youtube.com/watch?v=nUiDQd2NZpU I bet he can still get 20mpg even with that kinda power.
 

307 Regal

Royal Smart Person
Oct 21, 2009
1,667
915
113
Northern Indiana
I don't think you'll be able to do any of those for under 1000. There's the engine, transmission, crossmember, driveshaft (maybe), wiring, fuel system, pedals and clutch assembly (for the manual option), mounts, and exhaust just off the top of my head. You'd basically have to find a running donor car for under 1000 and do all the work yourself.
I'm not a fan of diesel, but I agree that it would be neat and it's even better that you know plenty about it. It'll just be expensive.

A 3800 swap would be very similar to an LS swap in price I would think. And then turbocharging it will be expensive, but more importantly it will endanger your car's reliability, which isn't good if you're using it to go back and forth to college. Don't give it too much boost and definitely invest in gauges if you go that route so you can monitor your car.

An Ecotech+trans would be just as difficult as putting in a diesel engine and trans I think. It might be good for long trips on the highway, but the engine will have to work hard to move your car in stop and go traffic. That'll effect your gas mileage. Also, if you wanna turbo this too, same as the 3800.

Vortec 350 would be like the 3800 swap but with more power and less gas mileage. And no extra cost and worry of a turbo.

If diesel is your thing then go that route. I don't really see any of these options having a clear advantage over the other so go with your gut.

P.S. A low power Olds 307/200-4R w/2.56:1 gears will get you at least 17mpg. Ask me how I know. :wink:
For starters, I'd just invest in an overdrive transmission that'll fit the 260, let that 260 breathe with a good exhaust and intake, tune it up, and see where that gets you.
While you're driving that back and forth to school, plan out your engine swap.
 

mheath717

Master Mechanic
Nov 13, 2008
413
19
18
Florida
Why not just buy a newer fuel efficient car to drive back and forth? And put your gbody project on hold for a while. Maybe you can eventually find the Monte SS that you really want. Just a thought.
 

DRIVEN

Geezer
Apr 25, 2009
8,062
14,479
113
*CENSORED*
I voted for the 3800 but I'd forgo the turbo. A stock Fbody 3800 swap should get low-mid 20s for mpg. Doubt it can be done for under a grand.

Although it isn't a listed option, you might consider an old 6.2 or 6.5 diesel. Don't laugh. They are reliable, cheap and literally bolt in place of a SBC. Our old 3/4 ton GMC work van got 20-22mpg with a 700R4. Your Cutlass will be lighter and more aerodynamic. I know it's not as cool as a Cummins but I don't think it's feasible to think you can do a 4BT swap for under a 1K. Should be no problem to do a Detroit swap for that budget.
 

Wild Card

Apprentice
Jan 5, 2013
61
0
0
you forgot to add a chevy 4.3 to the list. you can make one of them get up around 180hp easy. and thay are everywere.
 

dream on mcss

G-Body Guru
Jun 22, 2011
617
2
0
Oxford, MI
307 Regal said:
I don't think you'll be able to do any of those for under 1000. There's the engine, transmission, crossmember, driveshaft (maybe), wiring, fuel system, pedals and clutch assembly (for the manual option), mounts, and exhaust just off the top of my head. You'd basically have to find a running donor car for under 1000 and do all the work yourself.
I'm not a fan of diesel, but I agree that it would be neat and it's even better that you know plenty about it. It'll just be expensive.

A 3800 swap would be very similar to an LS swap in price I would think. And then turbocharging it will be expensive, but more importantly it will endanger your car's reliability, which isn't good if you're using it to go back and forth to college. Don't give it too much boost and definitely invest in gauges if you go that route so you can monitor your car.

An Ecotech+trans would be just as difficult as putting in a diesel engine and trans I think. It might be good for long trips on the highway, but the engine will have to work hard to move your car in stop and go traffic. That'll effect your gas mileage. Also, if you wanna turbo this too, same as the 3800.

Vortec 350 would be like the 3800 swap but with more power and less gas mileage. And no extra cost and worry of a turbo.

If diesel is your thing then go that route. I don't really see any of these options having a clear advantage over the other so go with your gut.

P.S. A low power Olds 307/200-4R w/2.56:1 gears will get you at least 17mpg. Ask me how I know. :wink:
For starters, I'd just invest in an overdrive transmission that'll fit the 260, let that 260 breathe with a good exhaust and intake, tune it up, and see where that gets you.
While you're driving that back and forth to school, plan out your engine swap.

Yeah I see your point. I was already thinking no on the 3800 swap because it basically require all the same kind of stuff an ls swap would need. The only way I'd do this swap is if i just bought a donor F-Body then I'd basically just rip everything out of that and have the PCM tuned. I appreciate the feedback though, as that's what I'm looking for to try and find the best option.

I wasnt really considering an ecotec, but I know they make decent power for what they are so I just thought I'd throw it up there anyways. To be honest I wouldnt want a little gas powered 4 cylinder in a muscle car anyways. A 4 cylinder diesel for sure, but not gas lol.

The reason why I threw the vortec 350 up there is because of the simplicity of it. These engines make damn good power in stock trim while still somewhat reasonably simple. If I was going to do this swap, it'd probably be carbed, which is the best of both worlds because it eliminates the weak central port injection system, plus it gets rid of the computer. I'm definitely going to consider this option.

Now, onto the Cummins, this would probably be the most pricey swap out there, with the motor probably costing more than that alone, but with the torque they make and the economy they get, plus the dead on fully mechanical reliability, it would still make for a fun car that can probably get 30mpgs on the highway. That and I'd probably be the only one on the face of the earth with a 4bt powered gbody, lol.

84Hurst/Olds said:
Why not just buy a newer fuel efficient car to drive back and forth? And put your gbody project on hold for a while. Maybe you can eventually find the Monte SS that you really want. Just a thought.

That's definitely something to think about, but I don't know man it just sounds like it'd be fun! Lol. Your right though, it would be alot easier, lol.

DRIVEN said:
I voted for the 3800 but I'd forgo the turbo. A stock Fbody 3800 swap should get low-mid 20s for mpg. Doubt it can be done for under a grand.

Although it isn't a listed option, you might consider an old 6.2 or 6.5 diesel. Don't laugh. They are reliable, cheap and literally bolt in place of a SBC. Our old 3/4 ton GMC work van got 20-22mpg with a 700R4. Your Cutlass will be lighter and more aerodynamic. I know it's not as cool as a Cummins but I don't think it's feasible to think you can do a 4BT swap for under a 1K. Should be no problem to do a Detroit swap for that budget.

Now that I've read your guys' opinions id definitely say no on the turbo now. And like I said unless I found a donor 3.4 or 3.8 powered f body that I could rip the drivetrain out of, then I wouldn't even consider it.

I agree with you on the v8 diesels though, that definitely sounds like a feasible option that could be done cheaply. I have a few GM repair manuals on the 6.5 as well and the one thing I love about diesels is that on most of them, you can get lots of power just by turning up the injection pump and running higher boost, very simple to do. I will definitely add that option to the poll. Like i said thanks for the opinions guys, I'm gonna try to price everything out and figure out the best option.
 

dream on mcss

G-Body Guru
Jun 22, 2011
617
2
0
Oxford, MI
Wild Card said:
you forgot to add a chevy 4.3 to the list. you can make one of them get up around 180hp easy. and thay are everywere.

Very true, while I did consider them, I have one in a 2000 blazer and the fuel economy is TERRIBLE so that's why I didn't put them up there, but I did now so be sure to vote. I imagine it'd get much better mileage in a gbody though.
 
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor