Looking at a 78 caprice classic with disc brakes. Is this a good donor for my 67 chevelle? What other parts could be useful on this car?

The front sway bar is about all you can use from the caprice, and then it won't be the desirable 1 1/4 diamater bar.
You will hear from others that the disc brakes can be adapted. Yes it is true they can be made to fit a 67 car but it will cause steering geometry problems, find the loaded spindles from a 69-72 a-body, 69 f-body, or 69-74 x-body, these cars use the correct spindle for your application.

Can't use the power brake booster?

This is straight from Global West's website. You will probably want new upper a frame arms. I just did it on my 67 - Fantastic graemlins/thumbsup.gif
The following donor cars provide 11-inch disc brake spindles:

Apollo 1975 GMC Sprint 1973-1977 Pontiac Full Size 1977-1981
Buick Full Size 1977-1981 Grand Prix 1973-1977 Pontiac Lemans 1973-1977
Buick Century 1973-1977 Monte Carlo 1973-1977 Riveria 1977-1978
Camaro 1970-1981 Nova 1974-1979 Seville 1976
Chevelle 1973-1977 Olds Cutlass 1973-1977 Skylark 1975-1979
Chevy Full Size 1977-1981 Omega 1975-1979 Ventura 1975-1977
Firebird 1970-1981 Phoenix 1977-1979

Donor for what parts? Brake parts?
The 78 will have the tall spindles if you are wanting to do the tall spindle conversion. But, if they only have 11" rotors, then I recommend you hold out and find a setup that uses the 12" rotors.

Otherwise, the rotors will not fit, the calipers have the banjo fitting in the wrong location, so you would need Caprice hoses, there are no caliper brackets (mounts built into the spindle!), the booster is likely to big of the large variety, but should still work, the MC should work if good, and the prop valve probably has the wrong braking bias due to the excess weight of the full-sized car. :D Is that what you wanted to know!?

Don't know of too many other parts you could use...

Bill C.

Yep, that is what I wanted to know. Think I will pass.