This weekend i performed a MiniMe Swap on my 1996 honda civic DX Coupe
I took my d16y7 head and intake manifold and swapped it to a d16y8 Head and Intake manifold and also swapped to an P2P ECU.

I went to start the car for the first time this morning and it did turn over and start but very poorly, like rpms in the 300's struggling.

now i did hear a vacuum leak and i have located it to be on the intake manifold where it bolts onto to the block. so it didn't get a good seal i guess? so i went to hardware store and got some gasket sealer paste and then took off the manifold and applied it on both of the gasket surfaces and bolted it back on. waited 2 hours like the instructions said and fired it back up, sounded like it was running worse and i still heard the leak -_-

I tried giving it gas and there is a big delay to it, just running really rough. it was spitting out white smoke from the back i looked that up,and that was said to be normal after a swap.

I let it run for a bit, the engine felt really hot, like it was going to overheat, i don't know why it would because it was full of coolant and the thermostat did pop

so now i am kinda stuck here, not sure why it running poor, maybe because of vaccum leak, i do have a vacuum gauge and that thing was just moving everywhere,
also not sure why it is overheating

Any help would be great, i am worried for my car :P
if there any other info you need know just hit me up.

White smoke usually means water is getting into the oil. Did you replace the engine harness aswell?