283 Chev Alternatives

Ive got a Ford Cortina mk4 that has been modified to take a 283 chev and gearbox. But Im having trouble finding one. Is there any other engines I could use that will fit the same engine mounts and are about the same size.
I suspect that the 327 and 350 chevs are possiblities but wasn't to sure if they used the same mounts or if they differ in size.
any help would be appreciated.
Thanks :)

you shouldnt have a prob there just go get ya a good 350 and stick it in there

Thanks just the words I wanted to hear.:) :)
A 350 sounds good to me ;)