I am clueless when it comes to Transmitters, Receivers, and Servos. I don't understand the voltage outputs or anything. I have a Futaba 2PL 2.4Ghz Transmitter that I purchased a very long time ago, and then it came with an R142JE receiver. I just pulled my car back out of storage and am upgrading everything. I was looking at the R603GF and the R203GF receivers and didn't know which one to go with because I can't find the differences. Both would work with my 2PL, right? Also, will either of these receivers work with a brushless system and any digital servo?

The R142JE is not a 2.4ghz receiver. Are you sure it is a 2.4 system? If its not you wont be able to use 2.4 receivers. Does your transmitter have a long metal antenna or none at all?

It has a long metal antenna, so you are right it isn't a 2.4 system. I got it way back so thats not surprising. I just assumed it was because whenever I searched Futaba 2PL all that ever came up was the 2.4 system. I guess mine is the Magnum 2PL. Looks like I will be in the market for a whole new system now. Any recommendations that are decent and not to pricey?

You don't need a 2.4 system. Brushless and lipo will still work just fine.

Exactly right. The Magnum radio will work just fine and now with everyone on the 2.4 kick you shouldn't have to worry about conflicting radio channels

Thanks for the input guys. I went ahead and got a Futaba 3PL because I wanted a 2.4 system and model memory for other cars in the future, and something with FHSS for faster response times.