Well, while I appreciate that vote of confidence, not sure how much help I can actually be on this one, but I'll try.
First off, I love Olds engines, they are my first choice when I want to play with some engine swap. But there are some things that you have to be aware of.
1) Olds changed intake manifold designs over the years, not all years fit all other years. I think the grouping is something like this:
49-53 the same, 54-56 the same, 57-58 the same, and 59-64 the same. I used to know for sure, but it's been a while. If you try to use a mismatched intake things like water necks and passages don't line up or aren't there at all.
2) The biggest problem with an Olds is the starter is on the drivers side and right in the way of most steering boxes. You need two things to move it to the right side, a special after market bellhousing lower section that has the provision for the starter on that side, and a oil filter block off plate or relocation plate. When you move the starter to the right side it occupies the same place as the oil filter and you have to get it eliminated or rerouted with hoses.
3) Stick setups can be a problem. Some Olds engines have cranks that are drilled for a pilot bearing and some are strictly for automatic transmissions. If yours is drilled you can use a stick bellhousing (I think 49 up is the same as are some Cadillac bellhousings from the early years) and the appropriate flywheel, clutch plate, etc. This stuff is getting hard to find though. Some places like Bendtsens sell an adapter to put a late model TH350 behind an Olds ($ 1000) or a stick bellhousing setup ($1500) Not cheap but nice stuff.
4) Another problem is that Olds engines have ONE motor mount in the front and two at the bellhousing, just the opposite of most American cars. You can get motor mounts that put two on the front for some engines, but not all of the Olds engines have provisions to bolt them on.
5) Weight is also right up there, I think these weigh about 700 pounds. An aluminum intake helps some, but not much.
All that being said, these are great motors. I have a 1964 394 in my current project, and I am using the Bendtsen adapter to put a th350 behind it. They make great power and are torque monsters.
Sounds like yours might be a 58? Just be careful about what intake you get and the other stuff, and you will be fine. The price seems good too, but these are a little expensive to rebuild. I have $ 3000 in rebuilding mine and it is only mildly modified.
Don
