Put some photos up. Original engine? - probably not a drama. I'd just put a V8 in it anyway? Drums or discs? (much bigger change from original that a V8 believe it ir not).

If it is in OK condition and complete it'd have to pull in the range of $5k-$15k, all dependant upon what it needed to be done to it. Broad range I know but without any more details it is very hard to tell.