Squarebody Differentials.

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.

idahovette

Full Access Member
Joined
Aug 7, 2016
Posts
7,348
Reaction score
16,081
Location
Weiser Idaho
First Name
Perry
Truck Year
1975-1979
Truck Model
K20-K10
Engine Size
350
Nope.




AND!

Still wish I had a 307 crankshaft to play with..






More than 2 quarts and less than 3.

Buy GL-5 fluid.
So Rusty, explain one more time about the 307 crank and all the other parts that you built. What block and what cubic inch do you end up with?
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,132
Reaction score
9,327
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Does anyone know if the Detroit locker came in the civilian full float 14 bolts or just the cucvs. My K30 is an 86 with a 454 all factory and original 88,000 miles and the rear diff cover has never been pulled. I know It either has 4:10’s or 4:56’s I’m just hoping and praying it’s not the gov lock. I’m going to pull the cover either Friday or Sunday, I’d just like to be disappointed before hand so that I’m not pissed off under the truck.


Sent from my iPhone using Tapatalk

Nope. If it's a G80 on your SPID label it's a Gov Lok. Cross your fingers and hope you have an open differential. Then you can add a Detroit Locker. If the 14b Full Floaters, cuz they're a split carrier, you can open them up and add any locker fairly easy and it doesn't have to Detroit Locker to be a good one. There's also Lock Right, IIRC the part # is 1455, there's one made by Yukon also, and another too that I'm currently drawing a blank.

If your axle is in currently good shape and doesn't need the ring and pinion set, the way the 14b is set up, you can mark the location of the carrier adjustment where it's currently set right now or count the turns on the side adjustments. Pull the carrier out, split it, install the locker, close it back up and reinstall putting it in the exact position it came out and then you know you didn't upset the current lash on the R&P but now have an installed locker.

If you have a Gov Lok, to bad. When it blows buy a new carrier and start from scratch. You can use your same R&P if they're in good shape and just reset all the adjustments to get the correct lash.
 

Curt

Full Access Member
Joined
Sep 11, 2017
Posts
676
Reaction score
1,142
Location
Loco Hills
First Name
Curt
Truck Year
1984
Truck Model
K-30
Engine Size
383
Does anyone know if the Detroit locker came in the civilian full float 14 bolts or just the cucvs. My K30 is an 86 with a 454 all factory and original 88,000 miles and the rear diff cover has never been pulled. I know It either has 4:10’s or 4:56’s I’m just hoping and praying it’s not the gov lock. I’m going to pull the cover either Friday or Sunday, I’d just like to be disappointed before hand so that I’m not pissed off under the truck.

The “No Spin” (Detroit Locker) was available in civilian Chevy trucks,special ordered.

There’s a few out there.More people ordered their trucks back then.
 

Cameron Covington

Junior Member
Joined
Feb 4, 2020
Posts
12
Reaction score
7
Location
Virginia
First Name
Cameron
Truck Year
1986
Truck Model
K30
Engine Size
454
Nope. If it's a G80 on your SPID label it's a Gov Lok. Cross your fingers and hope you have an open differential. Then you can add a Detroit Locker. If the 14b Full Floaters, cuz they're a split carrier, you can open them up and add any locker fairly easy and it doesn't have to Detroit Locker to be a good one. There's also Lock Right, IIRC the part # is 1455, there's one made by Yukon also, and another too that I'm currently drawing a blank.

If your axle is in currently good shape and doesn't need the ring and pinion set, the way the 14b is set up, you can mark the location of the carrier adjustment where it's currently set right now or count the turns on the side adjustments. Pull the carrier out, split it, install the locker, close it back up and reinstall putting it in the exact position it came out and then you know you didn't upset the current lash on the R&P but now have an installed locker.

If you have a Gov Lok, to bad. When it blows buy a new carrier and start from scratch. You can use your same R&P if they're in good shape and just reset all the adjustments to get the correct lash.
Thank you so much, that’s what I thought, I’m pulling the cover tomorrow.


Sent from my iPhone using Tapatalk
 

Snoots

Full Access Member
Joined
Jan 23, 2013
Posts
8,877
Reaction score
18,713
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350 w/203
I haven't found anything on this so I'll ask:

1. Has anyone done anything to their rear axle to cool the diff fluid WITHOUT adding a pump?
2. I know PML has a unit but it costs +$200.
3. Thoughts? Ideas?
 

Frankenchevy

Proverbs 16:18
Joined
Jan 3, 2018
Posts
6,098
Reaction score
7,805
Location
USA
First Name
Jeremy
Truck Year
Square
Truck Model
CUCV
Engine Size
Small
I haven't found anything on this so I'll ask:

1. Has anyone done anything to their rear axle to cool the diff fluid WITHOUT adding a pump?
2. I know PML has a unit but it costs +$200.
3. Thoughts? Ideas?
Not sure. if you haven’t already, maybe try synthetic fluid...

I have a buddy who is a legit wheeler guy/fabricator. He said to avoid this finned covers for a DD—that the OEMs have the shape figured out and that the aftermarket ones don’t fling the oil right and it can aerate, froth and cook.
 

MikeB

Full Access Member
Joined
Apr 4, 2014
Posts
1,782
Reaction score
1,020
Location
North Texas
First Name
Mike
Truck Year
1969
Truck Model
C10
Engine Size
355
So Rusty, explain one more time about the 307 crank and all the other parts that you built. What block and what cubic inch do you end up with?

Just jumping in here to say you can use a 307 crank in a 350 block to build a 327. I did that many years ago using SCAT 5.7" rods and Speed Pro hyper pistons. It was certainly a better solution than using a 50+ year old small-journal 327 block.

307 crank balanced for heavier 327 pistons:

You must be registered for see images attach
You must be registered for see images attach
 

idahovette

Full Access Member
Joined
Aug 7, 2016
Posts
7,348
Reaction score
16,081
Location
Weiser Idaho
First Name
Perry
Truck Year
1975-1979
Truck Model
K20-K10
Engine Size
350
Never really knew much about the 307 engines, that was at the tail end of my "performance" days. I built a 301 out of a bad 283 block and a good 283 crank, got pistons from Gratiot Auto Supply, either Chicago or Detroit, can't remember which. Really spendy about 40-45 bucks at the time!! Set of 461 1.94s and it really rattled if you didn't put the good stuff in it. ETHYL (the gas) was 31.9 or 32.9 cents a gallon at that time, really put a strain on the old pocketbook! Engine lasted around 8,000 miles then a cylinder wall caved and I sold the whole car for $300....56 Chevy 210 2 door wagon, then I bought it back about a year later, nother story!!!!!
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,137
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
mmm hmm

hay sorry I missed this dated October reply.

most 327 cranks are SMALL JOURNAL
LARGE JOURNAL 327 cranks were only built in 1968 and 1969
however! let not your heart be troubled...307 crankshafts have the same stroke (3.25") and were all LARGE JOURNAL - made from 1968-1973, in much more pedestrian applications ...Therefore your chances of finding a 307 crank that is good enough to USE, is exponentially higher.

What I really want to do is use a .030 over block , 307 crank, 6 inch rods, and off the shelf 383 pistons with a single pattern camshaft around .470 lift with about 0.30 head gaskets .. I think they make 0.34..THAT IS an easy 400 hp recipe on pump gas with 1.94 heads that displaces 331 cubes. Stock oiling and damn near a 6700 rpm redline.

BUT! I own a 267 v8 - made for three years 1979,1980,1981. if I de-stroked it with the same 307 crank,,I can run 6 inch rods and displace 250 cubes.

a 250 v8, not an I6.

I think a 267's pistons are only 3.5" in diameter though. yes. Which lends itself to off the shelf Chevrolet 3.1 V6 pistons from a Camaro...91-96?. i think. been awhile! not too long a window for the right v6 pistons in your v8.
 
Last edited:

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
30,595
Reaction score
28,800
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
mmm hmm

hay sorry I missed this dated October reply.

most 327 cranks are SMALL JOURNAL
LARGE JOURNAL 327 cranks were only built in 1968 and 1969
however! let not your heart be troubled...307 crankshafts have the same stroke (3.25") and were all LARGE JOURNAL - made from 1968-1973, in much more pedestrian applications ...Therefore your chances of finding a 307 crank that is good enough to USE, is exponentially higher.

What I really want to do is use a .030 over block , 307 crank, 6 inch rods, and off the shelf 383 pistons with a single pattern camshaft around .470 lift with about 0.30 head gaskets .. I think they make 0.34..THAT IS an easy 400 hp recipe on pump gas with 1.94 heads that displaces 331 cubes. Stock oiling and damn near a 6700 rpm redline.

BUT! I own a 267 v8 - made for three years 1979,1980,1981. if I de-stroked it with the same 307 crank,,I can run 6 inch rods and displace 250 cubes.

a 250 v8, not an I6.

I think a 267's pistons are only 3.5" in diameter though. yes. Which lends itself to off the shelf Chevrolet 3.1 V6 pistons from a Camaro...91-96?. i think. been awhile! not too long a window for the right v6 pistons in your v8.

The Camaro 3.1 was used '90-'92. But any iron-headed 3.1 will use the same pistons. Pistons from an aluminum headed 3.1 will make for much lower compression.
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,137
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
ok cool..whatever . :shrug: - somethin like that.

GM parts interchangability is the Shiznit.

xc_hide_links_from_guests_guests_error_hide_media

1968 307 cranked engine with 1992 v6 camaro pistons.
 

MikeB

Full Access Member
Joined
Apr 4, 2014
Posts
1,782
Reaction score
1,020
Location
North Texas
First Name
Mike
Truck Year
1969
Truck Model
C10
Engine Size
355
What I really want to do is use a .030 over block , 307 crank, 6 inch rods, and off the shelf 383 pistons with a single pattern camshaft around .470 lift with about 0.30 head gaskets ..

Unless my math is wrong, a 383 piston with the common 1.425" compression height would stick up .025" above a 9.025" deck, and even more if the block was decked to clean it up and square it. So to get, let's say, a .040" quench height, you need a .065" gasket. Am I missing something here, such as the availability of much shorter 383 pistons???


I think a 267's pistons are only 3.5" in diameter though. yes. Which lends itself to off the shelf Chevrolet 3.1 V6 pistons from a Camaro...91-96?. i think. been awhile! not too long a window for the right v6 pistons in your v8.

I doubt the 267's 3.5" bore x 3.48" stroke would make for anything close to a performance engine. It's essentially a more feeble version of the 305.:eek: A 265 or 267 with their larger bores and shorter strokes would be high performance by comparison. And a 307 even better. However, if you put that 267 in a 2,500 lb Chevy II, it might be OK, and definitely different.

Not trying to knock you out of the tree here, just making some comments.:) I'm always interested in unusual combos and the smaller SBCs.
 

Madmacs

Junior Member
Joined
Mar 6, 2021
Posts
13
Reaction score
4
Location
TN.
First Name
Dave
Truck Year
1984
Truck Model
K10, K20
Engine Size
350
Hey Mike, I remember those days Sunoco 260 ,top dollar premium, mix your own fuel ,for drags.
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,137
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
@MikeB
I dont know? Lol I just got turned onto the different wrist pin heights of some 383 pistons and identify that as good information that I prolly want to know more about.
The 267 is in fact, near the very back of my garage and I think it's actually underneath those tires.. That's the extreme back-burner. I got one though and I think it's awesome. I wanna build a 250 V8 one day because that would be cool AF.

WAY before that? I'm thinkin pretty damned hard about how to TunedPort this 408 sos I can stick it in the IROC...but right now i'm workin 6 days a week.

Don't worry. I don't forsee de-stroking this 400...lol...gonna let it be and stick gooder heads on it.

My Monte Carlo only weighs 2700 lbs. ;)

No tellin what will happen this summer!
I am NOT open-minded nor optimistic regarding the political climate in the country and IMO the smart money ain't spenden it on ******** like unique engine combinations.. I believe that window of opportunity has closed and change my plans accordingly.

In the meanwhile? That block aint botherin nobody under them tires..they're hard to find.
The point of that story was happy because I believe i'll be able to find an off-the-shelf piston.
 
Last edited:

Forum statistics

Threads
44,401
Posts
956,724
Members
36,714
Latest member
MartinK5
Top