To expand on what the previous replies have stated, I recommend that you put ONLY the required information on the data plate, even if the data plate you have has room for more info. For an experimental aircraft, there is NO regulatory requirement for the date of manufacture, the gross, weight, address of the builder, or any of that info to be on the data plate. Just list the builder name, aircraft model, and aircraft serial number, and leave any other available spaces blank.
And to reiterate what Vic said, make sure those three items of data match the info on the registration certificate exactly. If the builder name shows a middle initial on the registration, make sure it is also on the data plate. Conversely, if there is no middle initial on the registration, leave it off the data plate as well. Another place where people get messed up is the serial number (especially when not using a kit serial number). For example, if the serial number on the registration is 001, then it can't be 01, or just 1, on the data plate. Same goes for aircraft model. If it's Van's RV7" on the registration, don't put only "RV7" on the data plate.