Highway Speeds

Ok guys I just picked up a 400 sbc for my 47 IH. My goal is to be able to cruise on the highway at 80 with no problems. What would be the cheapest tranny/rear end combo to go with on my rat? Any advice sure would be appreciated!

I would think cheap would be a turbo 350 and a 2:73 or 3:08 rear and some taller tires.

RPM said:

I would think cheap would be a turbo 350 and a 2:73 or 3:08 rear and some taller tires.

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I'm running a th350 with 3.08 gears on 28 inch tall tires with my 350. I asked a lot of guys if they thought mine would be good for highway speeds and they said yes, as long as I kept that tall of a tire. They said I would be bouncing between 3rd and 4th all the time if I went with overdrive.

Cheapest for a Chevy would be a 350 tranny and you can get a good rear end from a Ford Vic for about $150-$200. They typically have around a 3.0 ratio and many have disc brakes.

Toad

80?????? Where is there a highway posted 80mph??

OUTLAW= IHC said:

Ok guys I just picked up a 400 sbc for my 47 IH. My goal is to be able to cruise on the highway at 80 with no problems. What would be the cheapest tranny/rear end combo to go with on my rat? Any advice sure would be appreciated!

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Just kidding....[cl Yep, 350 2:73 or 3:08 gear, tall tires, will give you the most bang for your ...gallon... 200r4 or 700r4 with the same 25% better or more.... .67 or .68 O/D.....like dropping the rear gear to a 2:35 / 2:45 or so....maybe better route.... 700R4 has a nice low 1st gear for good acceleration.....JMHO

Yeah I'm pretty much stuck between the 350 and 700r. Im runnin tall cokers, so thats a plus. I'm leaning more towards the 700r specifically for that lower gear but I'm think I'm just gonna go with whatever my wallet/wife allows me. Lol...I guess you really can't go wrong eather way. Thanks for the input guys! By the way, anybody know much about chevy colorado rear ends? I heard they are posi trac and cheap.

700r with 3.08's works fantastic.
I've got a 700r, 3.50's, 27" tall tires in my 56 Chevy and that works pretty good too but, the 3.08's would be better.
If you go with the 700r get a mid 80's to early 90's the early 80's is really weak.

Amen brother.!!!....

Old Iron said:

700r with 3.08's works fantastic.
I've got a 700r, 3.50's, 27" tall tires in my 56 Chevy and that works pretty good too but, the 3.08's would be better.
If you go with the 700r get a mid 80's to early 90's the early 80's is really weak.

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Them early ones are full of surprises!! (i.e. weaknesses)

sgtpontiac said:

Them early ones are full of surprises!! (i.e. weaknesses)

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I've heard the latest 700 you should get is an 86. Before that they were problematic.

I prefer the 700R4! I like the low 1st gear the high 4th. After my 1st one... I ripped out all the 350's & replaced them with 700's & 3.73 rear gears. MUCH better on the road!!!

BoB

Tripper said:

I prefer the 700R4! I like the low 1st gear the high 4th. After my 1st one... I ripped out all the 350's & replaced them with 700's & 3.73 rear gears. MUCH better on the road!!!

BoB

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Dangit tripper! Don't go changing my mind about my setup when I'm this far along and that much closer to being finished!

I guess I'm confused???

jmlcolorado said:

Dangit tripper! Don't go changing my mind about my setup when I'm this far along and that much closer to being finished!

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I thought this thread was to get ideas on what to use?? Do you have the motor and trans all in place? If so, run with it and down the road you can swap out the 700....or am I just confused???[S

sgtpontiac said:

I thought this thread was to get ideas on what to use?? Do you have the motor and trans all in place? If so, run with it and down the road you can swap out the 700....or am I just confused???[S

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It is to get ideas on what to use. The OP was wondering on what to use and the 700 was brought up. But since it was brought up, it's starting to sound like a better option for me later down the road.

I've got the tried and true 350/350 combo which has defiantly proven itself in this world so I don't think he could go wrong with it.

Nope....it is a proven combo and reliable...

but if you are looking for MPG and and a solid base...the 700 is the ticket...
Whatever you chose...you can change later.....cause "rat rods are never done"....or is it "finished"?? I'm done....or is it "finished"??

Well I have to throw a little wrench in the gears.......if you go with a 700 then use at least a 3.50 gear. You have to consider where the engine is most efficient, been lots of articles written about it. I once took a basically stock truck with a 302, overdrive(E40D), 3.55 gear and changed to a 4.10 gear and picked up some serious mileage on the highway. The gear brought the RPM's into the engines efficiency range.......
Just some food for thought

No arguement about basic stock trucks.....

motrhd said:

Well I have to throw a little wrench in the gears.......if you go with a 700 then use at least a 3.50 gear. You have to consider where the engine is most efficient, been lots of articles written about it. I once took a basically stock truck with a 302, overdrive(E40D), 3.55 gear and changed to a 4.10 gear and picked up some serious mileage on the highway. The gear brought the RPM's into the engines efficiency range.......
Just some food for thought

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but when you combine a lightweight vehicle into the mix it drastically changes the overall power band of the motor.....I've seen dual wheel 1 tons that do a lot of towing benefit from a gear change to a step higher numerically gear (3.73 to 4/10)set to bring the power band up so the motor isn't lugging under a load.....but with a 2500lb car I don't think you will see that type of benefit by going steeper.....the motor might nearly always be in the "power range" or close to it due to the weight to power ratio....JMHO....

The power band issue is legit.
The 400 sbc Outlaw is workin with will not like a higher rpm.
The sbc 400 likes 1800 to 2200 for mileage and will still have a lot of grunt.
2000 at 70 and 2500 at 80 is plenty.

Highway speeds

Thanks for all the info! anybody hear anything about those chevy colorado rear ends?

They are.......wait for it.....

OUTLAW= IHC said:

Thanks for all the info! anybody hear anything about those chevy colorado rear ends?

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"Rocky Mountain High priced"......lol....sorry couldn't resist......

Yep, the best thing to do is do the Automatic over-drive, the 700r., that way you can have performance like acceleration with managable gears and have good motor rpms out on the highway for cruising/ fuel economy.
You could always go with a gear vender also, if you had the room. But, for what you want, the 700r seems right....especially with those tall tires....
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