engine swap question

I just did the exact same thing in my 67 barracuda- switch from a '67 273 to a '73 318 and I used the same mounts (except new) without difficulty.

Can you be more specific? Same mounts as ?what? You used all 67 parts, or all 73 parts?

I put a used 360 in my 67 Dart, I used the original 273 brackets. That engine came with the huge van Bx00 brackets. I needed one more hole in the passenger bracket, was able to bolt one pickup bracket over the top of the 273 bracket, bolt them together, and drill the extra hole

On the driver side, I needed an extension below the bracket. Wish I'd taken photos. I bolted the 273 bracket to the engine, took a piece of ??3/8 X 1 1/2" strap, trimmed it to fit, and attached to the original bracket. Don't remember, I think I drilled and bolted it to the bracket. Wish I'd taken photos.

My recollection is that the van brackets use the same "pad" mounts as the 273, so I just picked the 2 that were in the best shape. It seemed to go in per normal.

If the engine isn't visibly horribly out of level (you DID check body level?) I would not worry too much. After all, when you are driving on a typical crowned road, it's sure not level.