Wheel size for 69 imperial ??

[KEISUKE]

I’m 27years old Japanese man.
I recently bought a 1969 Imperial coupe that has cut wheel stud bolts because last owner was using wide tread spacers with terrible looking 18inch rims.
And I want to replace the stud bolts for safety and better looking wheels, but I don’t know the size of stud bolts and PCD for this car.
Some say it has 1/2inch diameter 1.5mm thread bolts and 5inch PCD, others say 12mm diameter 1.5 thread bolts and 4.5inch PCD.
which is true???

 

[Big_John]

1/2-20 UNF is the thread size. Since the car is a 1969, you'll have right and left hand threads. Chances of finding the proper left hand studs are kind of slim, but right hand studs can be used.

To understand Imperial threads, 1/2 is the outside diameter of the thread. 20 is the number of threads in an inch and UNF is Unified National Fine or shortened to fine thread (versus UNC or coarse thread)

From the parts manual, the red arrows point to the correct studs you need. Sometimes you can match the part numbers to a replacement.

 

[Boydsdodge]

I use these studs often. More Information for DORMAN 610103

 

[Big_John]

I use these studs often. More Information for DORMAN 610103

I see that number for the rear and this number for the front.

More Information for DORMAN 610126

 

[CBODY67]

Welcome and congrats on your acquisition!

The front and rear studs can be different, not in the thread sizes, but in the amount of the "shank" where they index/fit through the rear axle shaft flange (on the rear) and the front wheel bearing hub (on the front), which can also impact their total length.

On the more vintage Chrysler products, the wheel stud threads were such that they always tightened toward the front of the car. There was a good theory for that, but in real world dynamics, was not really needed. All other vehicles tightened clockwise, no matter the side of the car they were on.

Lh wheel studs and nuts can still be found via the repro vendors, but as normal rh studs and nuts are much more common (and lower priced), plus the other situation, rh studs/nuts commonly replace the lh items on the lh side of the car.

Take care,
CBODY67