Can anyone tell me will a 3 speed wiper switch from a B or C body fit the e body? Also, does it matter if it is a standard or rallye dash?

No & Yes

I now of someone using a 71 B-body in a an E-body it fits and functions but would not be correct. It's also a lot cheaper

The e-body is really a variable speed switch not really just a 3 speed, not sure if that comes into play as well. And yes the standard dash wiper setup is almost completely different from the "3 speed" with the rallye dash. Linkage parts, wiring, switch, motor, more different parts than the same.

I know that I need the 3 speed motor, link arm (off the motor) and a bushing(?) to change to a 3 speed. I have the whole linkage setup out of a 3 speed car too though not sure if I need all the linkage but probably be easier just to use that set up.

Correct, all the wiring is the same. I have a non rallye dash, so do I need a non rallye 3 speed ebody specific switch? And if I understand correctly, the non rallye is different then the rallye switch?

I would like to change over to a rally dash at some point as well.

You will need (in addition to what you listed) the 3 speed linkage as well as the correct switch, the standard wipers are just 2 speed and no variable speed function.

The wiring is different as well, not sure if you can ad/change the existing wires or if you need the correct harnesses.

I have been collecting all the parts to do the swap myself and just got a rallye dash harness so I didn't have to mess with the wiring differences (I am swapping the whole standard to rallye dash setup).

Hi Challenger, I bought all new wiring from YearOne, though I went with the non rallye option. I am not sure if the new harnesses have the ability to use either 2 or 3 speed setup. I need to switch to a 3 speed wiper because I am adding a shaker setup. Did non rallye dash shaker cars use different harnesses?

Good question, I assumed you needed the rallye dash to get the 3 speed wiper, but maybe it was a separate option. I think most (if not all) of the shaker cars were R/T's which would have had the rallye dash.

Shaker will fit with a 2sp

NS1, it does? I did not know that. How much clearance is there? Have any pics??? Hopefully I won't need to convert them!

Just found this hemi cuda on ebay. Has standard dash but 3 speed wiper??? So is it the same 3 speed switch as the rallye dash then?? https://www.ebay.com/itm/1971-Plymouth-CUDA-Hemi-4-Speed/264286661676?hash=item3d88b66c2c%3Ag%3AeaoAAOSwcwdctmxQ&LH_ItemCondition=3000%7C1000%7C2500

https://www.ebay.com/itm/1971-Plymouth-CUDA-Hemi-4-Speed/264286661676?

try this.

70-71 ebody's used a variable speed switch not a 3 speed. There are 2 separate connectors that go on the switch. One has around 4 wires the other just 2. A 3 speed switch will cause a dead short and start smoking the minute you put the second plug on it. They will work on 1 speed if you leave the 2 wire connector off. The way I know this is they had the wrong switch in mine when I bought it and it would only work on 1 speed and park. I found the 2 wire plug off and thought that was the problem. Wrong quite a surprise when it started to smoke. It had the later 72-74 3 speed switch. The trick is the plugs are the same for the switch but where the wires go are different. The wiper motor itself is the same and will work either way, Lol

Here's a factory switch which I believe was used no matter which dash you had.

https://www.ebay.com/itm/Mopar-1970-71-E-Body-Variable-Wiper-Switch/223670458910?