Yes, your 235 will have a different bellhousing pattern than that of a V8 or later inline six cyl. However you can get an adapter from stovebolt engine co.( www.stoveboltengineco.com/index1.htm ) or fabricate one for yourself so that you could put an automatic tranny on your 235. Because of the gearing in the rear end on your '58, I suggest you look closely at an overdrive tranny, like a 700R4. This will allow you to do highway speed, instead of being limited to 50-60mph.
If you already have a V8 in your truck, you should be able to bolt up an auto tranny directly to it.
