Saginaw vs TRW Rack & Pinion ID.

I am about to order a rack for an 86 Laser and they made two types, TRW and Saginaw.

I would like to order the right one the first time and not wait 2 days, get the wrong one and wait 2 more days for the right one. I know Murphy well.

How can I tell them apart?

If I have to take a wild guess are they 100% swappable? Coupling, hoses, pump etc.

If they are 100% interchangeable is one better than the other?

Thanks

I'll add a bump.