i'm missing one of the bolts from the front engine mount, that connects the chassis to the engine, I broke it while swapping engines, so what size are they? thanks.

 

I dunno, but they come with two. Take the other one to a hardware store, and fine another one that matches. Just remember that bolts have a grade index on them, this ones probably 9.8 or 10.8. just make sure not to get a bolt that is of lower grade and you'll be fine.

 

It'll have either 10mm x 1.25 or 10mm x 1.5 threads. Look for grade 8.8; it'll work ok. It may have a 17mm head on it. Stock Mazda is 14mm.