Nailhead to 455 swap

[sd-slider]

Is it possible to use a 400, 455, or other GM engine where a Nailhead once was?

If any, are the mods major?

Any advice would be appreciated.

[HilbornNailhead]

I can't offer a whole 'lot of advice, other than to say I am going to be giving this a try this winter in my '57 Special. I'll be attempting a 455 swap, and I do know that both the 455 and the 364/401/425 Nailheads are 28 inches wide.

What car will you be doing this in? I imagine a later year, '60s car would be a heck of a lot easier than a '50s setup.
I know I'll be running into a lot of custom exhaust work, and maybe an issue with the steering column?

You ought to check out the reference section here, as there's a lot of good stuff on dimensions and weights (you'd actually be dropping a few pounds going from a Nailhead to a Big Block!).

Good luck with whatever you do, and I'd be interested to see how everything goes!

[nailheadnut]

The difficult part depends on what year. Up through 60, Buick used a torque tube rear end. The torque tube fastens to the rear of the transmission. In order to do this in an earlier vehicle, you'll have to completely redo the entire rear chassis to accept a rear end that incorporates u-joints.

[sd-slider]

What car will you be doing this in?

A 66 Skylark GS that had a 401 Nailhead.

[lentzjj]

I have been thinking about doing this to my 62 lesabre. I can bye a 455 w400 transe cheeper then i can get my torque converter rebuilt. Anyone know it the drive shaft splines are the same?

[wkillgs]

A 66 Skylark GS that had a 401 Nailhead.

The 67 GS used a 400, which is the same series as the 455.
You will have to get the frame pads and engine mounts, headers, a new radiator, and engine wiring harness. Depending on where the 455 is coming from, you may need to buy a rear-sump oil pan and pickup.
The nailhead trans won't fit the 455, so you need a different trans and shorter driveshaft. New Trans crossmember mounts need to be welded onto the frame. And if you have a floor shifter that will need to be modified to fit and work with the 400 trans, or find a 67 GS shifter.
That should do it....you still want to do the swap?
TA Performance has most of the necessary items.

It would be far easier to keep the 401!

[sd-slider]

I guess I should cut to the chase......

I have a complete 1987 Buick GN drivetrain waiting to go somewhere...

I read an article about a guy named Tim Lee who dropped the same drivetrain into a 65 'Lark with very little modification...

1965 SKylark GN

My primary question was whether or not you could replace the mounts, tranny support, etc. on a GS and have a clean install without violating the originality of the frame and related components?

Maybe I'm just Nuts!

[ARTMAN]

Do you still have the 401? I am in desperate need for a Rear sump Oil Pan for 401
Let me know
Art