[mongocanfly]

nope ..not even a need to change gauges...your oil sender screws right in the LS where it does on a smallblock...you will need metric to npt adapter...your water temp can feed from your pass side head..the driver side head is where the ecm reads from..
all the LS harness needs is a switch on hot ,a constant hot, and grounds...you will need to wire in the fuel pump but that's no biggy...it feeds from the harness fuse block...I would recommend a quality aftermarket harness..i used PSI..there are others as well..depending if your going to run elec fans or not ,those will need wired thru relays to the harness fuse block..they are controlled by the ecm..

depending on what trans you use..you can adapt from pulse to cable driven and you can keep your stock speedometer..i used a dakota digital convertor on mine

the LS will drop right in with adapter plates and stock small block motor mounts...you may have to move your trans crossmember depending on your choice of trans...