Hello I recently purchased a 66 Bonnie Convertible, it is in need of total restoration, it is complete but does have some rust in it. I was told by the prior owner that the car had a 421V8 however, it doesn't have 421 badges at the bottom of the front fenders, how can I tell if it does have a 421 or a 389?

Is it worth fixing up a restoration project like this or can I buy a decent convertible for 10-13K ?

Does anyone have an idea of what they are selling for in very good driver condition, like say, cosmetically restored etc?
Thank you for your input and feedback.
Regards,
Steve

I've been uber busy and missed this post. If it doesnt have the badges at the bottom on the chrome at the back of the front tire, it isnt a 421. Also, all 421'* I know of came with tri-power in 66. So I'm betting you dont have them either. The 62-66'* are my favorite Bonnevilles. Hope to see you post some pics.

Thanks so much for your response. I appreciate your feedback. It must not be a 421 because I certainly don't have tri-power. Does anyone know what parts I can use off of Catalina Convertible? I have an opportunity to buy a complete Catalina Convertible but it is to far gone to restore, and I was going to try to use the majority of the convertible parts for the Bonnie, or save many of them for spares if most are interchangeable etc.

There were 3 different 421'* in 66 . A 338 ***** 4bbl, a 356 horse 3x2 and a 376 horse HO 3x2.

Let me know if I can help.

The Catalina is shorter at the rear end. Everything else should fit just fine..

There were many 421s with the single Carter 4bbl carb...

Ron at Clear Creek restores these cars and knows them like the back of his hand.. Give him an e-mail...He'* a real nice guy...

Clearcreek Restorations - Home

On the block look for a YH, YJ, YZ or YM, . Those are the engine codes for a 421. However, if it doesn't have the badges, or at least 3 holes in the front chrome skirt piece then it may not be one.

Plain Jane Cats, GPs, Bonnes were 389s (4bbl on Gp standard and maybe on Bonne also).
I had a 65 Gp for 25 years and the 421 run down was as listed in post above.

I drove a 2+2 HO 4sp once ... damn!!! All 2+2'* in 65 and 66 were 421s.

I would think the VIN code would tell of engine combo but I don't remember and gave all my shop and body manuals to buyer.

emblem holes is a pretty good simple check though. see link.

1966 Pontiac Bonneville Convertible 421 Emblem Photo

The VIN will not tell what motor a pre 72(?) car will have.

here is a link for engine and head codes
www.classicalpontiac.com
go to the restore link, click the block or head code, and click search
hope this will help
after doing quite a bit of research, the YF engine block code is a 389 with head code 92, they were installed only in the incomplete Bonneville cars sent to Superior Coach for conversion to ambulances, hearses, flower cars and limos from 63 -67.