`70-72 GSX REAR SPOILER DIFFERENCES`

by Duane Heckman

I am often asked the following two questions regarding 70-72 GSX rear spoilers:

1. How can you tell a reproduction from an original, and 2. How can you tell the correct model year of an original spoiler?

To be honest, some of the reproduction rear spoilers out there are pretty nice, and it is getting harder and harder to tell them apart from the originals. Now this is not necessarily a bad thing, because it means we have nicer parts to fix our cars, but it certainly doesn't help with this discussion. The main differences between the reproduction and original rear spoilers have to do with vent hole size/location, weight, and pedestal width. Another difference is the fact that some of the reproductions are quite wavy across the top. This means there is more work required to "smooth them out", but once finished they do end up looking like the originals.

Without having an example of each reproduction, I figured the best way to tell the spoilers apart was to list the measurements and characteristics of an original spoiler from each of the three years and let you, the reader, decide the differences. So let's get on to the pictures. Here is a picture of an original spoiler from each of the three years.

The pictures (72 top, 71 middle, & 70 bottom) show the vent holes underneath the spoilers and have all been aligned with the centerline of the Spoiler at the same location. (Note the pictures were all taken from behind the car, looking up at the underneath of the spoiler.)

If you use the trunk lock as a centerline guide, it is easy to see that the vent hole placement changes for each year. The 70 spoiler has 1 hole approximately at the center point, while the 71 has 1 hole at the center and another towards the driver side, and the 72 has 1 at the center and the other towards the passenger side. It is hard to tell from the pictures, but the 70 vent hole is much smaller then the 71-72 holes, and is often absent, due to being filled in by bodywork when the cars are repainted.

The spacing between the holes also varied depending on the year, with the 71 holes being 3" apart and the 72 holes being 3.75" apart (shown in picture).

The pedestal widths are also different depending on the year. The top picture is from the 70 spoiler and the pedestal measures approximately 4.25" from tip to tip. The right picture is from the 72 spoiler and shows the length of the 71-72 pedestals at approximately 4.75".

The weight of the spoilers also varied, depending on the year, with the 70 spoilers being approximately 6-7 lbs lighter then the 71-72 spoilers. Summing up all the various differences gives us the following lists:

`1970 Original Rear Spoiler`

Vent Hole (A single 1/16" hole drilled approximately at the mid point of the spoiler. This roughly centers the hole over the trunk lock once installed on the vehicle.) Pedestal Width (Measures 4.25" from tip to tip.) Weight (Approximately 9.25 Lbs.)

`1971 Original Rear Spoiler`

Vent Hole (Two 13/64" holes, with one drilled at the mid point of the spoiler, and the other drilled 3" toward the left side of the car. This centers the one hole directly over the trunk lock and the other toward the driver side of the vehicle.) Pedestal Width (Measures approximately 4.75" from tip to tip.) Weight (Approximately 15 Lbs.)

`1972 Original Rear Spoiler`

Vent Hole (Two 13/64" holes, with one drilled at the mid point of the spoiler, and the other drilled 3.75" toward the right side of the car. This centers the one hole directly over the trunk lock and the other toward the passenger side of the vehicle.) Pedestal Width (Measures approximately 4.75" from tip to tip.) Weight (Approximately 16.5 Lbs.)

Conclusions As you can see from the above discussion each year spoiler is different, but by looking at the number, size, and location of the vent holes, as well as the size of the mounting pedestals, you can visually distinguish the differences even when they are mounted on a vehicle. Enjoy.