carfax for what? if it's a legit block? ask the guy for paperwork, a copy of the title to the car he got it from, or run it through your local police department.

3500 is on the higher end of the scale I've seen the motors go for. guessing that its 600miles since a rebuild? or original 600 miles?

 

original miles, its a long story, i have the motor i ended up buying it and damn all i can say is im happy as fuk

 

dude its an easy swap no biggie just try to get the pcm for that motor and use all the stuff from your usdm.good luck bro