Swaps Other than LS or LT

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

1STLS1

Full Access Member
Joined
Dec 9, 2018
Posts
210
Reaction score
526
Location
West Phoenix AZ
First Name
MIchael
Truck Year
1985
Truck Model
K10
Engine Size
350
I am in the middle of doing a frame up on my '87 GMC short bed step side. My original intention was to drop a used Goodwrench 5.7 and reman trans I have sitting around and use it for my daily driver for the next couple years. Recent fuel prices have made me begin to rethink this a bit, 14 mpg isn't very attractive. I could do cam, heads, chip and get 17 mpg. A LS or LT swap may do a little better.
Anybody heard of somebody dropping a new Camaro 2.0 turbo and 8 speed in one? Or a 3.0 diesel with a 10 speed? It's going to be similar money as a LT swap and would have to get better mileage along with performing better than the old 350 TBI.

Any better ideas for a max fuel economy square that runs decent? Old 6.2's got great mileage but were just too darn slow.

I saw the discussion about dropping a Ford Ecoboost in one, I just couldn't do it. Yeah, great engine, just couldn't do it to an old square.

Thoughts?
Ideas?
$10K budget with some flexibility?
 

ulm4lyf

Full Access Member
Joined
Sep 17, 2019
Posts
92
Reaction score
191
Location
Texas
First Name
Trevor
Truck Year
1978
Truck Model
Sierra Grande 15
Engine Size
350
If you could manage the 3.0 Duramax with the 10 speed trans that would be sweet. I have that setup on my 2021 4x4 1500 and over 27,000 I'm averaging 25mpg.
 

1STLS1

Full Access Member
Joined
Dec 9, 2018
Posts
210
Reaction score
526
Location
West Phoenix AZ
First Name
MIchael
Truck Year
1985
Truck Model
K10
Engine Size
350
If you could manage the 3.0 Duramax with the 10 speed trans that would be sweet. I have that setup on my 2021 4x4 1500 and over 27,000 I'm averaging 25mpg.
Cool some real world feedback. The 2 wheel drive and lighter weight may do even better.

That 3.0 and 10 Spd is available much less expensive than any of the LT combinations. If I have some time this week I will call some places and see if anybody has swapped one yet or what the challenges are.
 

ulm4lyf

Full Access Member
Joined
Sep 17, 2019
Posts
92
Reaction score
191
Location
Texas
First Name
Trevor
Truck Year
1978
Truck Model
Sierra Grande 15
Engine Size
350
There are several videos on Youtube where people have put Cummins 4bt engines into squares. If I had the money, I think that I'd look into that.
 

MattCone_TX

Junior Member
Joined
Aug 30, 2022
Posts
1
Reaction score
0
Location
The Woodlands, TX
First Name
Matt
Truck Year
1986
Truck Model
C10
Engine Size
5.3 LS
Curious how you'd handle the gear selection and indication on the 10 speed. I have a 5.3 LS in my 86 but i'm running a 700R4.
 

1STLS1

Full Access Member
Joined
Dec 9, 2018
Posts
210
Reaction score
526
Location
West Phoenix AZ
First Name
MIchael
Truck Year
1985
Truck Model
K10
Engine Size
350
There are several videos on Youtube where people have put Cummins 4bt engines into squares. If I had the money, I think that I'd look into that.
I was an equipment mechanic for a number of years and have worked on, well leave me rephrase that, changed fuel filters on 4BT for a long time, they just don't break. They are anvils, you can't hurt them. They can be modified to work well, get good fuel economy, make great power. I just want something more refined and modern.
 

1STLS1

Full Access Member
Joined
Dec 9, 2018
Posts
210
Reaction score
526
Location
West Phoenix AZ
First Name
MIchael
Truck Year
1985
Truck Model
K10
Engine Size
350
Curious how you'd handle the gear selection and indication on the 10 speed. I have a 5.3 LS in my 86 but i'm running a 700R4.
One vendor I saw uses a cable set up to operate the column shift for the 6, 8 and 10 speed GM transmissions, lots pretty simple.
 

eskimomann209

Full Access Member
Joined
Jan 9, 2019
Posts
1,849
Reaction score
2,005
Location
Modesto
First Name
Marcus
Truck Year
1973
Truck Model
C10
Engine Size
5.3
One vendor I saw uses a cable set up to operate the column shift for the 6, 8 and 10 speed GM transmissions, lots pretty simple.
Do you have a link for this?
Hell I’d be interested in seeing it.
I use the 4L60e in my stock column but I just don’t or can’t go into 1st gear without it throwing off my indicator.
But I’d be interested in a cable that can be fine tuned.
 

RecklessWOT

Full Access Member
Joined
Feb 20, 2015
Posts
2,556
Reaction score
4,764
Location
New Hampshire
First Name
Kevin
Truck Year
1987
Truck Model
V10 Suburban Silverado
Engine Size
350 TBI
How about a big block? Lol

I was unaware they ever put 2.0 turbos in Camaros, I knew they offered the iron duke for a few years but didn't think there was a performance option and they were all just dogs that people bought to look cool in a Camaro and ignore performance. Also I feel like an LT1 swap would be far cheaper than any LS or other modern diesel swap with a 10spd transmission etc. As they're still not really popular I feel like an LT1/LT4 could be had for a few hundred bucks from a junkyard and would still bolt up to a normal transmission. There's some simple electronic stuff going on but nothing compared to an LS swap, and being a little more of an "old school" real 350 it is like 1,000 times cooler than any LS garbage someone might toss at one of these poor trucks
 

SquareRoot

Full Access Member
Joined
Mar 18, 2017
Posts
4,198
Reaction score
8,044
Location
Arizona
First Name
Mike
Truck Year
85
Truck Model
K20
Engine Size
350
THIS!
I have the Duramax version of this in my AT4 and it gets 35 mpg average, sounds cool as hell and tows 7700 lbs.
 

Attachments

  • 2.8 Cummins.JPG
    2.8 Cummins.JPG
    62.4 KB · Views: 79

1STLS1

Full Access Member
Joined
Dec 9, 2018
Posts
210
Reaction score
526
Location
West Phoenix AZ
First Name
MIchael
Truck Year
1985
Truck Model
K10
Engine Size
350
Do you have a link for this?
Hell I’d be interested in seeing it.
I use the 4L60e in my stock column but I just don’t or can’t go into 1st gear without it throwing off my indicator.
But I’d be interested in a cable that can be fine tuned.
I don't know how they view outside vendors on this board so I will just ask for forgiveness if I'm wrong... :)


The guy that runs that site is really cool and super knowledgeable about the swaps. He took the time out to answer a bunch of questions I had when I considered a LT1 swap a couple years ago. He also does wiring harnesses and tuning.
 

oldretiredafguy

Full Access Member
Joined
Apr 20, 2020
Posts
1,419
Reaction score
3,235
Location
N. Texas
First Name
Mike
Truck Year
1988, 1988, 1991, 1983
Truck Model
GMC V-Jimmy, GMC Suburban 4WD, GMC Suburban 4WD, GMC-2500 CrewCab
Engine Size
350, 350, 350, 350
How much do you drive on a daily basis that you're so worried about gas mileage? None of my business, but part of the attraction about driving our old squares is the looks from mere mortals, plus I've never met a woman who doesn't like a bench seat so they can cuddle up against the lucky driver/owner of said square. I know Phoenix has grown since I lived there in the mid 70's, hopefully it hasn't gotten as bad as LA, or DFW, or God help us like Bangkok.
 

eskimomann209

Full Access Member
Joined
Jan 9, 2019
Posts
1,849
Reaction score
2,005
Location
Modesto
First Name
Marcus
Truck Year
1973
Truck Model
C10
Engine Size
5.3
I don't know how they view outside vendors on this board so I will just ask for forgiveness if I'm wrong... :)


The guy that runs that site is really cool and super knowledgeable about the swaps. He took the time out to answer a bunch of questions I had when I considered a LT1 swap a couple years ago. He also does wiring harnesses and tuning.
Looks like they have some cool items in there. Thanks for that.
 

1STLS1

Full Access Member
Joined
Dec 9, 2018
Posts
210
Reaction score
526
Location
West Phoenix AZ
First Name
MIchael
Truck Year
1985
Truck Model
K10
Engine Size
350
How much do you drive on a daily basis that you're so worried about gas mileage? None of my business, but part of the attraction about driving our old squares is the looks from mere mortals, plus I've never met a woman who doesn't like a bench seat so they can cuddle up against the lucky driver/owner of said square. I know Phoenix has grown since I lived there in the mid 70's, hopefully it hasn't gotten as bad as LA, or DFW, or God help us like Bangkok.
A honest answer is it most likely doesn't matter. I think I would drive it more often if it wasn't the least fuel efficient. Like today, I have a beater '05 Ranger that gets 21 mpg no matter how I drive it and I tend to drive more because it gets the best mileage. Just something in my personality, I'm cheap
 

TotalyHucked

Full Access Member
Joined
Feb 24, 2020
Posts
3,679
Reaction score
11,891
Location
Auburn, Georgia
First Name
Zach
Truck Year
1985
Truck Model
Sierra 1500
Engine Size
5.3
I think it'd be cool as hell to do something different. Mine is LS swapped cuz that's what I'm familiar with and is pretty simple/budget friendly. The 3.0 Dmax/10-speed would be awesome. I bet you'd get 30+mpg, I get 22 with my cammed LS
 

Forum statistics

Threads
44,204
Posts
951,585
Members
36,335
Latest member
crew
Top