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As I understand things, Packard engines were built with studs rather than bolts. Is studs the right word?

More to the point, why would either be preferred?

Pat, that's an all-encompassing and global statement and not correct. For example, referring to cylinder heat attachment, the in-line Packard engines used studs and nuts, the V8 Packards used bolts. Most Chrysler in-line engines used bolts for cylinder heads. Engines are a mixture of both in one place or another and there are several reasons for an engineer/designer to select one over the other for a specific application. Properly sized, there is no inherent difference in the final application of clamping force; one of the several reasons for choosing one over the other is ease of future service.

If you want the strongest and most accurate clamping force and the most likely to stay the same over the life of the car, then studs and fine thread nuts are the best choice.

Bolts are cheaper. Coarse thread bolts cheaper yet, and can be rammed home in seconds with an air powered wrench on an assembly line. Not as strong or accurate but "good enough" for a cheap mass produced product.

Studs are usualy used in Al. Especialy if CI is the attached part. Usualy a coarse thread is used in any casting. A fine thread at the other end for strength or compactness due to limited space. Ergo the stud.

There are many other factors as well as exceptions. Best to use bolts unless you're running extreme service conditions. Studs present problems for disassembly due to corrosion. Problems if dpace limits disasembly.

There are many factors to consider. For general civilian applications such as what the home shop experiences the studs are best avoided.

If u dont believe bolts are better than studs then go get a Jag v12 aboout30 yeard old and 120k miles (boat anchors, u can usualy get them for free) and try removing the head. You better be a bad boy to try it.

Another good example for stud application is exh manifolds where exh pipe attaches. Coarse thread into CI. SAE on other end for a stover nut due to heat.

Claims of more strength and more even torque etc has a very slight.margin of truth. But its tantamount to claiming $100 is better $99.98.
Thats my ten cents. Two cents is free. A nuisance with no sence???? No one cent for me????