When installing a Y-Block into a project car/truck, this question is with the understanding the pinion angle will be adjusted after the engine is installed. At what angle should the top of the intake manifold be when installing motor mounts to accommodate a Y-Block? Frame is at ride height, pinion angle will be corrected when transmission tail shaft and differential housing are installed.

Darrell Howard

Whitefish, MT

Darrell Howard Whitefish, MT Outlaw 56 Ford F-100's

Ideally the carb flange should be level with the car's springs in the normal loaded condition. 

Doug T

The Highlands, Louisville, Ky.

Doug,

I'm thinking if I place a straight edge from the front eye bolt hole to the rear eye bolt hole of the rear main leaf, measure that angle, and set the carb flange at the same angle, I will  have the parellel you are making reference to in your response. Is this correct?

Darrell Howard

Whitefish, MT

Darrell Howard Whitefish, MT Outlaw 56 Ford F-100's

As a practical matter, in original vehicles like early 50's Ford PU trucks and cars the bottom of the frame was level with the ground as built.  So if that is what you are working with then set the frame on 4 equal height jack stands on a level floor and then level the carb flange.  But these days with so many combinations of things like mono springs, IRS conversions dropped axles etc that may not be sufficient.  Of course it is not completely necessary to get the carb level to run the vehicle but it is very helpful when setting the float levels.

With regards to the drive shaft and rear axle alignment, the ideal design is that the centerlines of the engine, transmission, drive shaft, and rear axle pinion all be in line.  Obviously when the vehicle goes over a bump or carries a different than expected load, the U joints come into play and allow the movement of the rear axle.  If I remember correctly from machine design of 40 years ago, if the centerlines (in this case of the trany and pinion) are not aligned then they need to be parallel.  Also the centerlines of yokes on the drive shaft must be in the same plain and parallel. This prevents a vibration. 

I have not had very many drive shaft problems over the years and there are undoubtedly people reading this site that have practical experience in these matters. They are encouraged to jump in.

Doug T

The Highlands, Louisville, Ky.

Here is some very good info on drivelines. Just click on each of the "more" and it will open up a pdf file.

http://www.iedls.com/guide.html



marv

Marv

Thanks for sharing the great reference for anyone building a custom Chassis.  BTW it confirmed my somewhat shaky memory.

Doug T

The Highlands, Louisville, Ky.

Your welcome Doug.



I have used that info several times when installing FMX's in the 56's as one has to mfg a new transmission mount support. It works as drive lines are quiet.

marv

As usual, thanks everyone for the response/s, its always to have some experience in the equation before the welding begins!

Darrell Howard

Outlaw 56

Darrell Howard Whitefish, MT Outlaw 56 Ford F-100's