Rear Upper Shock Access Holes in Trunk -1970 Challenger

[DY31970]

Hi, I'm planning to install a new pair of Bilstein rear shocks in my 1970 Challenger. I looked at the shop manual on how to remove the rear shocks and it reads, it is necessary to remove rubber plug in luggage compartment to gain access to upper mounting bolt, in order to remove. I looked at my newer trunk pan which the second previous owner to me had installed. It doesn't have any plug holes.
It does have the 2 flat topped raised sections where the access holes should be. What diameter should the holes be? I found a Mopar parts supplier that has the metal plug and orange neoprene washer, which are 2- 1/2" diameter. Shouldn't the holes be smaller? If anyone knows the diameter or can measure the hole diameter please let me know. I've also seen pictures of the access holes with black rubber plugs in them, which is correct?

 

[budascuda]

I don't know the exact size, but In later years, they punched the holes on the upright part of the pan so the access holes would face the nuts directly rather than from above, I guess they realized at the factory that it was easier to remove the shocks with a socket wrench,
You could do the same if not concerned with originality, it sure makes more sense. .

 

[Juan Veldez]

I have a 73 Chally. It calls for an orange plug. The hole is 1 7/8" dia.

 

[MoparCarGuy]

1970-only has the shock bolt access holes at the top. Challenger and Cuda hole sizes are the same other than the gas tank filler tube's oval cutout location.

 

[Cratos]

i was able to do mine from underneath as long as the bolts come in from the front side.

 

[DY31970]

Thanks budascuda. I saw a 1971 'Cuda at a Mopar show in June with the access hole and plug on the upright part of the floor pan. I'm thinking about doing that.

 

[DY31970]

Thanks for the picture Juan Velez. The location of the access on your 73 Challenger makes sense. I found out a 1970 Challenger uses black plugs.

 

[DY31970]

Thanks for the pictures MoparCarGuy, They really help. From the white Challenger photo, would you know what the 1" plug to the left is for? Also from the 1970 Cuda pan, would a 1970 Challenger pan have the 4 X 1/4" drilled holes for the exhaust hangars in the same location?

 

[Steve340]

The one inch plug is an access hole in to the chassis rail.

 

[MoparCarGuy]

Thanks for the pictures MoparCarGuy, They really help. From the white Challenger photo, would you know what the 1" plug to the left is for? Also from the 1970 Cuda pan, would a 1970 Challenger pan have the 4 X 1/4" drilled holes for the exhaust hangars in the same location?

As noted, the 1” plug to the left is directly above the framerail. No real use for that plug. Another 1” plug is further back near the taillight and is also above the framerail.
The exhaust hanger plates (2 x 1/4” bolt holes and one or two smaller holes for each plate) are in the same area of the trunk for Cuda and Challenger. I will post a modified pic for Challengers. The area around the plate is somewhat formed to “frame” the plate's location.
Note: The 1/4” holes are only there to insert the exhaust hanger bolts. Some plates have two extra holes in the exhaust hanger plate for Phillips head screws. The repro plates (pictured below with Limelight paint) have a center hole and one hole in the corner but not all cars have both of these holes (see original plate below with Red paint).
A single exhaust car would only have one plate so the other side would not have the 1/4” holes. I put together a graphic for single vs dual exhaust using factory service manual diagrams. See below.

 

[DY31970]

MopaCarGuy, I'm glad you included the information and pictures of the 1/4" holes for the exhaust hanger bolts. My trunk pan does have an indentation for the location of the plate. I'll have to get the plates and drill the holes. I'm going to install the factory style dual exhaust. I'll be installing the heat shields under the trunk pan. I have the shields and bolts. would you have a picture of where the heat shield bolts come through the trunk pan? I wasn't finding specific info for the heat shields bolt locations in the shop manual.

 

[moparlee]

The heat shields do not have any additional holes up thru the trunk floor pan. The two rear slotted holes of the heat shield use the same two holes as for the exhaust hangers. The heat shields go on first then the exhaust hangers. The two holes on the side of the heat shields get self tapping bolts that go into the side of the frame rails. Then the one hole at the front of the heat shield has a self tapping bolt into the shock cross member.

 

[DY31970]

Thanks very much moparlee. I found these photos and I can see front of the heat shield uses the 2 bolts for the exhaust hangar, the heat shield going in place first. The second photo shows the side of the heat shield bolting into the frame rail with two bolts. Are the holes already there for the side bolts of the heat shield? Or will I need to drill holes in the frame?

 

[MoparCarGuy]

The holes for the heat shield side bolts to the frame should already be there. Passenger side frame rail of 70 Cuda shown below.

 

[DY31970]

Thanks MoparCarGuy.

 

[terrywalker]

Just for information purposes. Some 1971 Challengers came with the top mounted shocks access plugs. My Dec 1970 built Challenger.
Terry