inline 250 with 373 posi???

[ooimpalaoo]

so i have a 1969 c10 dont know what gears are in it now but when i go up hils i get honked at in the slow lane. my truck has a t5 tranny 235/75r15 not once have i been able to use my fifth gear. i dont even care about that fifth gear i just want to be able to have a little fun in my truck. use the fast lane to go up some hills and honk at other people. lay a patch if thats possible???? 250 inline 2barrel carb long tube headers, so duel exhaust. i was told to put a set of 373 gears in.. i found a 373 posi is that the way i want to go ? or what do i need to do here? thanx for the help yet again. was trying to find a video on youknowwhattube but i couldnt...

[Coley]

If your truck came from the factory with a 6 cylinder engine (check the spid)....
then you already have the 3:73 diff.
If your truck had come with a V-8 then your truck came from the factory with a 3:07 diff.

All Good
Coley

[ooimpalaoo]

ok i did swap the rear out for a five bolt i forgot. the stock was 6 bolt. i cant open the case and look its my daily and i dont have time if im not swapping it. ill try and spint the tire trick to check it.. but would 373 posi be what i want?

[Mrturner1]

Originally Posted by ooimpalaoo

ok i did swap the rear out for a five bolt i forgot. the stock was 6 bolt. i cant open the case and look its my daily and i dont have time if im not swapping it. ill try and spint the tire trick to check it.. but would 373 posi be what i want?

Sounds like you need a SBC to me. Inline 6 is a great motor, and they make a nice little torquey trail motor for 4x4 in my opinion. Some guys even get a bunch of horsepower out of them. But if you want something to just drop in as is and spin the tires/do 70mph in the fast lane, then look for a 350

Gear ratio won't help you

[ooimpalaoo]

im not looking to drop a 350 into it. or a big block. lol but thanx for the idea.. i have lots of cars with small blocks. i want this 250.

['68OrangeSunshine]

I have a '68 C/10 Stepside, 292 L6, SM465, 12-Bolt Corp 3.73 Posi, 235/85/R16LT. Runs good and eats up hills. [The Posi I swapped out from a junkyard '69 GMC, back in the early '80s when the picking was good.]
I don't get why you're having a problem. What CFM carb is your 2-bbl? Stock, or aftermarket intake? Do you have a crossover pipe on your dual exhaust?
Engine stock or modified? Points or HEI?
If you have an overdrive transmission, you should be able to use it.

[Grumpy old man]

[QUOTE=Mrturner1;7545379]Sounds like you need a SBC to me. Inline 6 is a great motor, and they make a nice little torquey trail motor for 4x4 in my opinion. Some guys even get a bunch of horsepower out of them. But if you want something to just drop in as is and spin the tires/do 70mph in the fast lane, then look for a 350

Oh my God ! Are you kidding me ? I'll smoke your 350 all day long with a 292 ! Let's say for titles ? And that "little" 292 will still have the torque to pull the trailer with your truck on on it all the way back to good ol Tn , AHHH , Grasshopper you've built 1 Well 1/2 of 1 Engine let's not get all that and the box of chicken just yet ! "gear ratio won't help you " WHAT ? Hahaha !
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[GASoline71]

GOM... nailed it again.

Gary

[Mrturner1]

Good grief I said they are great motors! lol I was complementing them, even said some guys (like you apparently) get tons of horsepower out of them. Let's not start taking low blows about my build. I was giving him a quick solution, doesn't sound like he wants to sink a bunch of money into it, and he mentioned swapping rear ends as a possibility. To me, that sounds like he's looking for a quick fix, which a small block would be. Changing gear ratio doesn't make a slow truck fast

I'll leave the one about racing alone lol.....

K&N filter and 44 psi in the tires should do the trick lol

[Mrturner1]

Originally Posted by GASoline71

GOM... nailed it again.

Gary

I can see you now with a jersey that says "GOM" on it, waving a flag that says GOM LOL!

[68350]

To me it sounds like you have 3.07 gears if you can't even use 5th. Did you find an entire rear-end with 3.73 gears or just the carrier and posi? I would say 3.73 or even 4.10 gears since you have overdrive. What gear are you trying to climb hills in?

[BrianG]

Originally Posted by Mrturner1

Good grief I said they are great motors! lol I was complementing them, even said some guys (like you apparently) get tons of horsepower out of them. Let's not start taking low blows about my build. I was giving him a quick solution, doesn't sound like he wants to sink a bunch of money into it, and he mentioned swapping rear ends as a possibility. To me, that sounds like he's looking for a quick fix, which a small block would be. Changing gear ratio doesn't make a slow truck fast

I'll leave the one about racing alone lol.....

K&N filter and 44 psi in the tires should do the trick lol

Sorry Matt, but you need to be careful on the advice you are giving. Like many tried to explain to you on your build, a set of gears might have made your truck with the old motor 'Come to life'. It's about getting the motor into the rpm band where it is making power when needed. Whether that be the torque or hp. So, gears could definitely make a slow truck fast. To the OP, I'd do like you plan and try to figure out your gear ratio. As far as posi or open, that's something you have to decide. Do you tow with it, plan on burn the tires take-offs that sort of thing, then maybe a posi. More of just a cruiser, maybe sometimes drive on icy roads, maybe open is better.

[Grumpy old man]

Put the 3.73 posi in and you'll be happy ,


Mrturner1 , A little good natured ribbing is all in fun . While your sitting at the line smoking your tires with that one wheel wonder a "little" 292 with a manual Trans and 3.73 posi will sit and git ! There were lots of 350 guys back in the early 70's who lost their shirts betting against the "little" l6 engines . It's all about correct balance and weight distribution and a taller gear just makes them quicker down the road . Learn to love the color of fading tailights ! Hahaha ! What will 44 psi in the tires do ? Help it spin faster ? Try 16 psi maybe it will hook up a little better , or rip out your driveshaft !
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[Grumpy old man]

Originally Posted by Mrturner1

I can see you now with a jersey that says "GOM" on it, waving a flag that says GOM LOL!

It's the shirt and hat that have GOM on them that flag he's waving is checkered and you just lost ! Hahaha !
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[Mrturner1]

Originally Posted by Grumpy old man

Put the 3.73 posi in and you'll be happy ,


Mrturner1 , A little good natured ribbing is all in fun . While your sitting at the line smoking your tires with that one wheel wonder a "little" 292 with a manual Trans and 3.73 posi will sit and git ! There were lots of 350 guys back in the early 70's who lost their shirts betting against the "little" l6 engines . It's all about correct balance and weight distribution and a taller gear just makes them quicker down the road . Learn to love the color of fading tailights ! Hahaha ! What will 44 psi in the tires do ? Help it spin faster ? Try 16 psi maybe it will hook up a little better , or rip out your driveshaft !
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I'm laughin with ya don't worry! lol the 44 psi and K&N was sarcasm, I was bein silly you know, like something that simple could change everything haha (takin a shot at the gear swap)

I still don't think gears makes a slow truck fast though gears moves the power in the rpm range. my truck would've benefited for sure (still will!) but it wouldn't have near the power it has now. Needed a stall too, man am I happy I got one of those.

My hat is off, and I am truly amazed and interested in learning more if I6's are beating SBC's at the strip What I was thinking was an I6 with granny low crawling all over the trails in the woods here where I live.

[Mrturner1]

Originally Posted by ooimpalaoo

dont know what gears are in it now but when i go up hils i get honked at in the slow lane. i just want to be able to have a little fun in my truck use the fast lane to go up some hills and honk at other people. lay a patch if thats possible????

Sounds like a SBC and 44psi is what he's lookin for to me!

[In The Ten Ring]

My truck came with a 250 and a 4.11 rear end.

I have been considering a 3.73 so I could go a bit faster but still climb WV hills.

[Mrturner1]

OP sorry we hijacked you, just having some fun I think you have an awesome rig, hope you get it goin faster! Fast is fun

[ooimpalaoo]

i need gears i know it. ok . so i do have HEI my exhaust has no H pipe. my 2bb i dont know the cfm its some carb i dont even know ill get a pic of what the last guy did. stock intake. ok so i tryed to do the jack up and mark the tire and axle then spin count and i was sloppy at it i was in a rush and ill do it right if this isnt close to gear ratio. because i dont know what they all are or what are good for what tire 10 turns. shaft 15 . so from what i saw its 1.5 but like i say i was sloopy is that right or close to anything? after looking more i guess it being a 12 bolt makes a dif as well does anyone know what i have from this ****y post??

[Grumpy old man]

Ok , you don't have a 1.5 rear so try that again and this time rotate the passengers side rear tire .if you have access to a 3.73 TRUCK 12 bolt posi BUY IT ! They are hard to find A car 12 bolt will not work . If your not sure take a picture and the guys in here will tell you what it is . Post some pictures of the truck and engine . What size tires are on it ?
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[ooimpalaoo]

Ok so this time I think I have it 37 and 10 so 3.7.....is that 3.7.3s lol?

[Grumpy old man]

Originally Posted by ooimpalaoo

Ok so this time I think I have it 37 and 10 so 3.7.....is that 3.7.3s lol?

Yeah , I would think its a 3.73
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[1970 charlie]

I have a 70 short step, stock 250 with a 3 in the tree no overdrive. I push cars up over hills if I had more pedal I would pass them and this is at 60/70 mph

['68OrangeSunshine]

Originally Posted by ooimpalaoo

i need gears i know it. ok . so i do have HEI my exhaust has no H pipe. my 2bb i dont know the cfm its some carb i dont even know ill get a pic of what the last guy did. stock intake. ok so i tryed to do the jack up and mark the tire and axle then spin count and i was sloppy at it i was in a rush and ill do it right if this isnt close to gear ratio. because i dont know what they all are or what are good for what tire 10 turns. shaft 15 . so from what i saw its 1.5 but like i say i was sloopy is that right or close to anything? after looking more i guess it being a 12 bolt makes a dif as well does anyone know what i have from this ****y post??

Stock '69 250s didn't come with 2 Bbl carbs. The Rochester Monojet was the only carb GM had for any L6s -- 230, 250, 292. Later when the Integrated Manifold was produced [Late '70s, '80s ?] some L6s had a 2 Bbl. If you have headers, it can't be the Integrated Manifold, as they were incompatible with anything but a stock exhaust. [Although I don't know a lot about the later stuff.] There was an aftermarket 2-into-1 adapter, but it raised the carb up 2 inches.
A picture would help.
Here's a driver side pic of my 292: Offenhauser intake, Edelbrock 1404 -500 CFM 4 Bbl carb, Clifford headers.

A note about the crossover pipe. It may be urban hotrodder legend, but crossover exhaust is supposed to help out with scavenging and improve low-end torque. [What you want when climbing hills and pulling loads.] The guy who did mine, an old midget-racing pit guy, told me that. He also calculated that since the collectors were asymetrical on the L6 -- with 1-2-3 in front of 4-5-6 -- that an angled cross tube would be better than an "H" pipe. So mine looks more like an "N". Another side effect is that as the pulses from the front cylinder pop, they are countered by the pulses from the rear cylinders and this cancels out their being heard at full volume by human ears.
Some voodoo, I know, but it works. I've been running the crossover for about 30 years, and I could feel it from day one.

[ooimpalaoo]

i have the same headers as you. in the pic as far as my 2bbr its not stock and my phone wont let me load it . it is the stock manifold and the PO made a sort of Y shape for a 2-1 adapter.