$300 is cheap, that way you will be in it right and you can afford to do some stuff to it

You can stick a 318 in there easy, mine had a 440
plenty of room

Seriously, I'd consider putting the bolt on parts on it ..It would be a nice quick option , others have done it and it works well

The lips of fools bring them strife, and their mouths invite a beating.Proverbs 18:6