Try finding a donor with a Nailhead

June 1, 2008 | By Richard Prince


I really like Auto Restorer as it features real people with real at-home projects! I have a 1963 Buick Riviera with the original 401 engine and automatic transmission. The engine started making a knocking noise while on a road trip, and wound up with a 11⁄2-inch hole in the side of the block. Most likely it threw a rod, although I haven’t taken the engine apart to see.

I would like to get the car running again as it belonged to my late son and we both liked the car a lot, but I have not had any luck finding a running 401 to swap into it.

I would like to know which engines or engine/tranny combinations would “drop in” without much trouble. Are there any that would be easy to find and, hopefully, cheap? The car has been sitting for over 12 years, so I have no idea how the tranny will be although it was OK when the engine blew up.

I have the tools and knowledge to pull and replace the engine and tranny but no experience with manufacturing motor mounts or complicated subsystem revisions and such.

My budget is pretty limited for this project so any help would be appreciated.


The 401 is a member of Buick’s “Nail-from 1957-66. Any big block Nailhead produced during these years will go into your Riviera without much trouble.

Your biggest difficulty may be finding a good running engine for a modest price. Good Nailheads are not exactly falling out of the trees these days.

Your best option may be to buy a good running car that’s very rusty, crashed, or otherwise damaged. Besides affording you the opportunity to evaluate the condition of the engine while it’s running, this would also provide you with a host of other, hard-to-find parts that you may need down the road.

As far as your car’s transmission is concerned, after sitting for more than 12 years I would at least clean and reseal it. If feasible, you are, of course, better off going through the transmission and replacing normal wear parts.