found a motor to replace my tired one. mine is a 99 honda accord 2.3 vtec 5 speed. found a 2.3 vtec out of accord with automatic. is the only difference going to be swapping flex plate to my flywheel. balance?

 

The engines should be pretty much identical, except for the flywheel, clutch, pressure plate.

 

Yep, take out the flex plate with 17mm 12 points socket and swap your fly wheel right over using the same bolts.

 

Just to make it clear, you need to use the flywheel bolts from your old engine. The bolts from the auto-trans car will be too short.

Check whether it's the same engine. F23A1 vs. F23A4 vs. F23A5 (VTEC or ULEV or not)