47-55.1 New to me 1950 3100 - Making plans

[JdavUGA]

I just purchased a 1950 3100 that looks to be mostly original.
I plan on making it a daily driver, so I want to do some safety & performance upgrades including disc brakes and suspension upgrades. However I am planning on keeping the original 216.

For the front, I will be doing a Mustang ii style swap (Scott's HotRods bolt in is my leading contender). I'd like to add electric power steering - any reco on what set up might work?

For the rear I have a few questions.
What gearing ratio is best? We'll be doing a mix of in town and highway driving.
I am leaning towards replacing the entire rear end rather than just regearing, it seems the s-10 4x4 would require the least alteration (keeping stock frame & ride height).
If I change the rear end gear ratios, will that require replacing the torque tube to a more modern open driveshaft?

It is currently a 3 on the tree, but I am considering putting in a 200 4R automatic. Any advice?

[mongocanfly]

Welcome....
To change either the trans or rear axle , you'll need to change both, and loose the torque tube..
Gear ratios will depend heavily on your entire drive train..
Trans final ratio, desired speed, desired rpm at that speed, and tire size..
Heres a rpm calc to help you figure it out..http://www.csgnetwork.com/multirpmcalc.html
And we like pics...show us your truck.....

[JdavUGA]

Thanks Mongo.
Are you saying that if i change the rear axel (and driveshaft) I'll need to change the trans (even if I don't go auto)?

As far as pics, happy to oblige
Here it is the garage we pulled it out of, where it has sat for 25 years:



And on the flat bed coming home:


After a much needed bath:


And after a long weekend of work pulling out the engine and other disassembly :

[mongocanfly]

Wow...that looks like a pretty solid truck..
Yes..you'll need to change it all to a open driveshaft..

[joedoh]

welcome! Thats a great looking truck!

scotts IFS is not a Mustang II, I think they even market it that way, and its got better geometry and more adjustement than a mustang II so I think you will be happy with it. scotts has a lot of experience with these trucks so make sure you get the right setup for the ride height you want.

the torque tube/trans/rearend, even the leaf springs are part and parcel, meaning if you change one you have to change them all. the torque tube rear axle pivots slightly so if you change the axle, you change the open driveline and that means change the leafs and the trans too. there was an open drive piece I think on the 3600 with the 4 spd granny trans that can be used on the 3spd 3100 trans, but the 1:1 top gear wont be a friend on the highway, so an overdrive trans will probably be what you want. but again, that means changing the rearend and leaf springs too.

to that end, i have heard good things about the speedway rear leaf kit for these trucks. using the s10 rear you will need to move the perches on the axle slightly. again, get your ride height in mind FIRST.

speaking of the highway, the 216 definitely doesnt like to rev, iit has babbit bearings and oils by splashes, if you really want a highway cruiser consider a full pressure oiled engine like a 54 or later 235. its not 100% necessary, the 216 will be ok if you keep the revs down.

[MiraclePieCo]

Congratulations on your new/old truck! Looks like it was stored under cover so that's definitely to your advantage. Start a thread in the "Projects and Builds" section!

[8man]

Good looking start. Welcome to the fun!!!

[JdavUGA]

Well, change of plans. I guess that’s expected with 70 year old trucks.
Cylinder #4 has a crack, debating on trying to find a 235 (what can I expect for price on a running one?) or L96. Going L96 would put the project on hold for budget reasons
Posted via Mobile Device

[mongocanfly]

Believe it or not, but the old 6cyl stuff is getting hard to find..I would think if you could find one ,$500 would be fair...when you talk LS, that's a snowball effect...you can spend little,to a lot...
Check around , carpart is a good place to start...https://www.car-part.com/mobile/index.htm

[JdavUGA]

I found a cheap, running 230, but trying to determine what other changes that would entail.
I understand Bellhousing, engine and trans mounts
Trans and rear end can stay if I get a late 50's cast iron bellhousing?

[JoeDude]

Originally Posted by mongocanfly

Believe it or not, but the old 6cyl stuff is getting hard to find..I would think if you could find one ,$500 would be fair...when you talk LS, that's a snowball effect...you can spend little,to a lot...
Check around , carpart is a good place to start...https://www.car-part.com/mobile/index.htm

Wish I could find a running 235 for $500. The one I'm looking into is in Minnesota. It is an older rebuild but includes the 3 speed trans. The shop is pulling it out of a '54 truck and testing it. It will come painted. They want $2800.

[mongocanfly]

Wow....I'd go LS before I dropped that much on a 6

[Tempest67]

The goals for my project were similar to yours, daily driver, reliable, power steering and brakes, comfortable, but I wanted to add a SBC with manual trans. (small block Chev)....why keep the 216?


why not pick up a running V6 S10 and put the old body on it? it will give you everything you want in 1 package for a fraction of the cost.(and you can test drive it before you buy it)

there is my 2 cents

[JdavUGA]

Update:
I have secured a 250 engine and TH350 trans (I will be changing motor and trans mounts and need to swap the fan)
Scott's IFS and 4-link rear suspension are on order

Next up is the rear end and I have questions.
This will be a daily driver including highway driving.
It will be stock height and I want good-sized sidewalls on the tires on 16 or 17" wheels.
What tire size can fit without interference (or tubbing)?
What rear end gear ratio should I go with?
And it seems a 61" mounting surface to mounting surface rear axel would be ideal?

[mongocanfly]

with the i6 and t350 I wouldn't go real low on the rear ratio..but youll need to nail down your rear tire size before deciding that,,
heres a calc to help you figure it...http://www.csgnetwork.com/multirpmcalc.html..
as far as spring perches , I wouldn't worry bout it...once you decide on a axle,those can be moved to fit the truck

[JdavUGA]

Yeah, that's my conundrum - I'm thinking a 27.5" tire (235/55R17). That would fit without any interference, correct?
Then 3.55 gears?

[mongocanfly]

https://tiresize.com/chart/ 27.2x9.3R17
that should have you turning about 2850rpm at 65mph with 3.55s.. thats gonna have the ol 6 singing the high notes
you may want to look more towards 3.08s..that would be 2473rpm at 65mph
a od trans would be great with the 3.55s..that would get you down just under 2k at 65
not sure on width.."may" fit with proper bs...may want to drop down to a 8in tire if you don't want to tub it

[mr48chev]

The height of the tire within reason isn't a big issue with stock height or close to it suspension. I didn't know that Scotts built anything stock height though

I'm thinking that a 255-55 anything is going to be on the wide side but if it isn't real low you should be ok. 8 inch wheels on the back are as wide as you can go without tubs and then you have to seriously watch your WMS to WMS on the rear axle width and wheel back spacing to have the right clearance inside and out.

There are plenty of rpm, tire diameter, gear ratio road speed charts and calculators on the net to let you figure out what your comfortable RPM range is.

I honestly don't remember If I ever actually checked the gear ratio in the mid 70's Nova rear axle under my 48 that has a 250 with a later 3 speed six and don't know the rpm at 70 but it would cruise comfortably at 70 on the highway and get 20 mpg when the engine was in good shape. I'm thinking it is a 3.0 though. The truck was daily driven for 15 years most of the time before the engine got so worn out (around 250K on the engine) that it wouldn't run.

This calculator is on a crawler page but it is real simple and easy to use and easy to get a basic idea of what your rpm would be at a certain speed, tire diameter and rear axle gear rato. https://www.crawlpedia.com/rpm_gear_calculator.htm

This one is on an build your own electric car site but a lot of us use and like it because you plug in three factors and get the fourth. It's quick and easy to use. http://advanced-ev.com/Calculators/TireSize/

[joedoh]

Originally Posted by mr48chev

I'm thinking that a 255-55 anything is going to be on the wide side but if it isn't real low you should be ok.

just a note, not a correction, I am running 255/35/20 on 9.5" wide wheels all 4 corners on my current truck lowered about 5 inches from stock 3100 and there is still a lot of room.

[mick53]

Originally Posted by JoeDude

Wish I could find a running 235 for $500. The one I'm looking into is in Minnesota. It is an older rebuild but includes the 3 speed trans. The shop is pulling it out of a '54 truck and testing it. It will come painted. They want $2800.

Beware of the slippery slope. My oil pump was $3500.

[mick53]

Originally Posted by JdavUGA

I just purchased a 1950 3100 that looks to be mostly original.
I plan on making it a daily driver, so I want to do some safety & performance upgrades including disc brakes and suspension upgrades. However I am planning on keeping the original 216.

For the front, I will be doing a Mustang ii style swap (Scott's HotRods bolt in is my leading contender). I'd like to add electric power steering - any reco on what set up might work?

For the rear I have a few questions.
What gearing ratio is best? We'll be doing a mix of in town and highway driving.
I am leaning towards replacing the entire rear end rather than just regearing, it seems the s-10 4x4 would require the least alteration (keeping stock frame & ride height).
If I change the rear end gear ratios, will that require replacing the torque tube to a more modern open driveshaft?

It is currently a 3 on the tree, but I am considering putting in a 200 4R automatic. Any advice?

I went with EPAS electric power steering. it uses the same kit as the early corvette. Works on all 2"column tubes. It has adjustable gain and torques off of the column so just cut a piece out of the column and run a power wire. You can clock it up under the dash.
https://shiftsst.com/electric-power-...-corvette.html
There is a video there. I have not installed mine yet but did get to drive one my friend put in. I really like it and so simple. I get to keep my OEM column. no pumps hoses pulleys or belts. Not cheap but I would have had to start from scratch anyway.

[JdavUGA]

We got the 250 running (on an engine stand), but there is one tapped hole in the head that I cant figure out what belongs there. Its on the driver side at the front of the engine. Any ideas?


Also, got the engine mocked up. It's going to be tight, but with some adjustment to the radiator and fan, I think I can make it work.

[mongocanfly]

Mine has that same hole..with nothing bolted to it

[JdavUGA]

Originally Posted by mongocanfly

Mine has that same hole..with nothing bolted to it

Thats an easy solve.

Thanks!

[whitedog76]

I was curious myself. Power Steering pump mount.