NVRPLUS28-7T, and NVRPLUS28-7/RT at amain hobbies.same price. the only differences i see are the 7/rt has roto start(can i still use my starter box with it?) extra venturies, a purple cooling head,a 500 rpm increase and different tuned pipe recommendations. it appears that i ordered the 7t and not the 7/rt. its going in a losi 8ight t 2.0. Im going to start racing soon and before i install the wrong engine i would like to ask for feedback. thanks a bunch.

It will work fine with a starter box, that is the only way to start it.  As far as I can see both mills are the same except the rt has the rotostart- but even the rotostart version can be started by a starter box too.  The only reason for the different pipes is probally because of header clearence on the rotostart version.  A engine that does not have a pullstart or rotostart on the back has a little bit of an advantage as there is no friction from the one way bearing that is used in the pull/rotostart versions.  One thing that you might want to look into is the amount of ports the track you are planning on racing at will allow.  Usally in club racing they are not very critical on maximum amount of ports but I think races that are sanctioned by ROAR  allow a maximum of 5 ports, I could be wrong as its been awhile since I attended a ROAR event, but it's something to look into.
Other than the above mentioned, you should be very happy with that engine, it is a great mill.