Engine swaps

[Odes Cain]

I wanted to know from you experts, can you put a 425 Nailhead in a 1968 Buick Riviera I asked this question because the 66 Riviera that I have has to much rust to repair after it was Sandblasting but I have a completely restored 425 Nailhead and I found a 68 that is close to where I live Thank you all for your expert opinions and advice in advance.

[61polara]

Post your question in the Buick section further below.  A lot of Buick experts there.

[Rusty_OToole]

Anything is possible but why? By 1968 they were using a much newer, more modern engine design that debuted in 1965. Engine was completely different, transmission different, and considerably improved. If there is something the matter with the 68 engine it would make better sense to rebuild it.

The 425 is considered the primo "nailhead" Buick engine and is in much demand from nostalgia hot rodders. You could probably sell it for a lot more money than a 1968 engine.

[RivNut]

The Buick big block first appeared in the 1967 models as a 430 in the full sized models and a 400 inch version in the intermediate models, the 455 appeared in the 1970 models. Highest hp rating for any Buick big block was 370 in thr 1970 Riviera.  The nailhead was in production from 1953 through 1966.

[Rusty_OToole]

RivNut thanks for the correction.

[EmTee]

I recall this question being asked before awhile ago.  The answer, technically is "yes", it it possible.  The first year of the 2nd generation Riviera was 1966, which was the last year of the "nailhead" (425 CID).  So, given that you have a '66 donor car, it seems to me that you could swap all of the drivetrain and drivetrain-related accessories and mounts from the '66 to the '68.  Someone like @JZRIV can probably identify specific things to watch out for.  For example, I think the starters are on the opposite sides of the 425 vs. the 430 and likewise the inlet and outlets on the radiator.  You'll need to pay close attention to differences in the engine bays once you have both engines out.  I don't know whether the driveshafts are the same lengths or not; chances are you'll need to use the one that came from the '66.

 

There are undoubtedly other things that you'll discover that will need to be adjudicated one way or the other (i.e., use the '66 pieces or '68 pieces).  This would certainly make an interesting thread to follow on "Me and My Buick" (https://forums.aaca.org/forum/58-me-and-my-buick/)  Good luck! 

[60FlatTop]

There is just something unnatural about putting a Nailhead in a '68 Riviera.

 

A couple of similar incidents.

 

 

[RivNut]

The nailhead has the distributor in the rear, the BBB has the distributor in the front.  Motor mounts are different and a few other things.

[EmTee]

There's another thread on the AACA Buick forum about recommissioning a '68 Electra.  The issue with that car is it wasn't stored properly and water got into the cylinders and messed up one cylinder pretty badly.  The new owner is contemplating a rebuild, however, my suggestion in that case also applies here.  That is, it would likely be much easier and maybe no more expensive in the end to simply find a serviceable used 430 or 455 engine.  That will certainly get the '68 running and driving with much less effort.  The '66 could be sold to offset the cost of the used 455.  Something to consider...