Where to start?

[AwesomeSauce]

Hey all I bought a Frankenstein of a D50 a few months ago and finally have the money to start fixing her up. I have a few questions and I'm not exactly sure where to post this. It's a 84 body on a 86 frame and the guy said that it has the 2.6 motor but under the hood says that it's the 2.0 G63B is there an easy way to ID which it is?

Anyhoo, the main question I have for you guys is that the guy I bought it from said that it has 462 axles and was running 35 inch tires on it. It came with 30 inch tires but they are junk. I'm not sure where I need to be tire size wise for optimal gear ratios. At 55 in 5th I'm running at 2.6k and the speedo reads about 61 MPH. I'm only getting about 14 MPH and I have the Weber carb so somethings up. I figured the gear ratios would be a good place to start.

Thanks for your help guys in advance!


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[pennyman1]

to determine which engine you got at a glance, look at the front on the motor, if the timing cover is black plastic, then it's a 2.0 g63B; if metal, it should be a 2.6. 4.62 gears are very desirable for large tires, but not for stock sizes. It should also make 1st gear useless. Post an underhood pic so we can be sure of what motor you got.

[AwesomeSauce]

Looks like It's a 2.2 . That would explain why the distributor cap I bought off of rock auto doesn't fit lol. :P


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[pennyman1]

no its a 2.6 - you also need to hookup the vacuum advance to the weber carb - it goes to a fitting on the side of the carb above the throttle plates.

[AwesomeSauce]

Sorry about that. I meant 2.6! :) So I'm going to hook up this14392 and put it on this?14393

Sorry. I'm new to these fancy carbureted engines lol

[AwesomeSauce]

I think I found it. Its not what I posted earlier. It's directly on the carb and has a cap on it. What size tube do I need? Sorry for being so new to all of this.

[pennyman1]

1/8th inch vacuum hose

[AwesomeSauce]

Just to confirm, This is what I'm hooking up for the vacuum advance on the carb right? 14399It's not 1/8 inch.

[Mandle]

Good looking truck! I love the first generations!!!
This is from BradMPH's thread called "Rebuild, replace, refresh" or something like that of his prized "Mitsy"
Here's the link to his whole build.
http://www.mightyram50.net/vbulletin/showthread.php/2390-quot-Mitsy-quot-86-Repairs-Renew-Rebuild-Replace/page4?highlight=mitsy

Page 4, post #87 describes the ported vacuum advance.14400

[AwesomeSauce]

Thank you much kind sir! Onto the proper gear ratio now. Can anyone with a tachometer tell me what they're running at 55MPH and what size tires they're running. I'm excited to get her where she needs to be! :)

[AwesomeSauce]

If anyone could help me get this back to the proper gear ratio I would gladly appreciate it! It's expensive to drive her as it is lol

[camoit]

The tires are to big. people always put on big tires and that kills the gear ratio of the truck. I know my rims were 14 inch. If you go back to stock it will clime a wall again.

[AwesomeSauce]

Yeah but I don't think it needs the 14 inch rims with the different axles right?

[AwesomeSauce]

Would a dealer know what the ratio should be?

[pennyman1]

the gear ratios available for 2wd ram50s are 3.55 and 3.91; 4wd are 3.91 and 4.22(rare).

[AwesomeSauce]

So I would do this http://www.how-to-build-hotrods.com/gear-ratio.html to find out where I am? How would I use what I get to figure out what size I need? Would I need another size tire to figure out the difference between tire size? Thanks for the help!

Also, which ratio is going to give the best MPG?

[pennyman1]

you have 2 issues here - the 4.62 gears are too steep for stock tires, but pretty good for 35" tires. 3.91 gears with the stock 225-75-15 tires would give you much better mileage.

[LSR Mike]

Some Formulas for ya'll

Tire Diameter Calculator
tire diameter = 2 x selection width x aspect ratio / 2540 + rim diameter
Width Aspect Ratio Rim Diameter Tire Diameter
225 60 15 25.62992126

MPH Calculator
mph = rpm x tire diameter / differential gear ratio x 336/ transmission gear ratio
Differential Transmission Transmission Transmission Transmission Transmission
Gear Ratio 1st Gear 2nd Gear 3rd Gear 4th Gear 5th Gear
3.909 3.74 2.136 1.36 1 0.856