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I am in the process of building a 1939 Ford Standard coupe resto mod. I recently received and installed a 383 Blueprint engine/700r4 package on a new TCI 4 link chassis. My next step is to order a new custom driveshaft. My first question is can I take measurements without the body on the chassis? I now have a rolling chassis with the engine and transmission installed at ride height but I am concerned that the body weight could change driveline angles and measurements. Currently I have a 5.7 degrees up angle on the engine transmission measured at the harmonic balancer. My pinion angle on my 9” Ford Currie rear is 3.2 degrees up measured at the face of the pinion. My concern is the difference between the two angles. My understanding is that both angles shouldn’t be more than 3 degrees. I can’t raise the transmission to decrease the engine transmission angle because the tail shaft will hit the chassis housing so is it ok to adjust the pinion angle with 4link adjustments to match the engine transmission angle? I am assuming these angles need to be set before I can get accurate measurements for ordering a new drive shaft. Any advice is appreciated.
 

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Race it, Don't rice it!
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Remove the springs and block the chassis at your predetermined road ready ride height for measuring.
Opposite and equal angles are ideal, seldom ever happen in the real world however. Even less on a custom build. You can move the rear end to get it closer to ideal, if you can get there. If not, do the best you can.
Drive shafts are made in 1/2 increments in most cases so all your specs need to be pretty close but don't absolutly have to be dead nuts. Just get the as close as you reasonably can.
 

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87 Dodge Dakota 6.1 hemi, 39 Chevy Master 85- work in progress
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Tremec has an app to use your phone to measure the angles. It sounds like your up and down are wrong. It will correct that.

Yes you use the pinion to fix the angle.
You only need to be close to measure for driveshaft. Couple degrees will not change much.
 

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87 Dodge Dakota 6.1 hemi, 39 Chevy Master 85- work in progress
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U joint angles should be 1-3 degrees. There is more than just getting them parallel.

Driveshaft angle is important, first figure would not work.

U joint angle is the difference between transmission and drive shaft and pinion and driveshaft.

When we hear back on driveshaft angle, can say if angles are good. If the car has the same driveshaft angle as transmission and the pinion gets set parallel it will have 0 angle but pass the parallel and eat u joints. If it's too steep it will vibrate and eat u joints.
 

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Read the information at the link below...
For starters, they state that the engine/transmission is typically installed at a 3-degree downward angle.
Also, they state that u-joints are designed to have 5-degrees or less angle between driveshaft and pinion/trans output shaft.
Lots of good info in their pamphlets.

Yes, your pinion angle and trans shaft angle should be the same, regardless of what the number is.

 

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Also, you should determine exactly what the ride height with everything installed will be.
Mock up the suspension (as someone else already mentioned), and measure for the driveshaft.
Of course, make sure that the entire drivetrain is installed exactly as it should be, since any changes after the fact could require having the driveshaft redone... $$$

EDIT:
Unless there's some reason you need to get the driveshaft first, the best route is probably to build the entire car, and leave the driveshaft for last...
 

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Offset the engine as much as clearence allows. Having your headers installed will help here.

This will minimize/ avoid compound angles.

Get yourself a digital angle finder that has a magnet on it like the one below.


They are worth every penny.

Install new u joints before finding/setting angles, have the driveshaft balanced, and if a long driveshaft consider a 2 piece.

If you must run angles of more then 3 degrees then consider running a constant velocity joint on the transmission end. These allow for more angle to be run.

Here is some tech on the topic.
 

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If you have one or two driveshafts around(usually using the old one) cutting them up and tacking them will let you see angles and make "free" changes with no questions left about what you will need for the custom driveshaft.
 

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The basic premise is that your rear end pinion will be closer to the ground than your transmission tailshaft. ie: lower to the ground.

The engine/trans is usually set for about a 3 degree downward angle and the rear end is set for 3 degrees upward.

Because the rear ends pinion is closer to the ground, they will be on the same angle, but not in the same plane.........as shown in the diagram a few posts above.

If you are running leaf springs, your rear end will tend to want to wrap up as torque is applied, and the springs will allow that to happen. The rear suspension will also allow the rear end (pinion) to move up and down. All of this changes the relationship between the rear pinion and the tailshaft. The idea is that having the pinion a little further down will allow it to be closer to the right angle when in operation.

If however you are running a four link rear suspension and coil over shocks, the rear end does NOT wrap up when torque is applied but does move up and down with the suspension. So a less initial downward angle can be used.

If your engine is tilted down 5+ degrees, I would check to see if you can lower the engines mounting position so you decrease the angle without having transmission interference probs .
 
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