I'm putting a 01 4l80e in the camaro a guy i know is going to rebuild it for me he said 1500 for the rebuild and he would guarantee it to 1000hp for a year street use is it possible to make one hold that hp for 1500?

a guy you know locally or what?

 yes its possible.  the 300m mainshaft and the billet drum are the only high dollar components.  then a set of clutches and thats about it.

i would say he is doing you a big favor on the 1500 but then again thats you bringing him a transmission core that you gotta buy somewhere else first for more money.

 getting a transbrake on there though will run you another g, and putting a good converter in front of it will cost you another g

also have to consider that he is probably betting you wont be making anything near 1000hp and probably does not have any history at all of building reliable high hp 4l80's.