I have found conflicting info on trans fitment. which nailheads use the B.O.P pattern? Is it all 401-425 or 1958 and later?
I want to use a 200-R4. I have found a '62 401. Will this work and if so what other parts do I need..... flex plate, torque converter, starter? Any help is greatly apreciated. I'd like to gather as much as possible before I start the swap.

Thanks,
Lee

None of the nail heads have a BOP pattern. They have a circular pattern that is not compatible with any other pattern. The only options you have are the Dynaflow or the ST-300 and 400 .If you have an early(pre 64 ) 401 it fits the dynaflow and to install the ST series trans requires some mods to the end of the crank.

thanks for the information, I'll have to make an adapter then. would any one else be interested in something like this?

Make an adapter for an overdrive trans and it will sell.

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Steve B.
GSCA #2173 (1986)
67 GS 525 Stg IV
66 GS Convertible
65 GS HT
63 Riv

i second that steve


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Sean Etson
64 special 300 pwr 12.72@105
64 skylark all original servivor
49 super modei 51

Folks on the Riviera mail list have been asking the same question.

Seems no-one currently makes an adaptor for the Nailhead/BOP conversion.

Yeah, I think you'd sell some!

what is ....B O P?...besides bop..as in do wap be bop! : )
how about a chevy 7004r tranny for a nailhead, has its own overdrive, good tranny....

It stands for Buick/Oldsmobile/Pontiac. The term first appeared in the early 30s as GM started closing and combining dealerships for the mid-priced brands in the Depression. The derisive term for it then was "BoPeep".

Try www.gearvendors.com (http://www.gearvendors.com) for an overdrive on a torque tube setup. I'm not sure if it'll clear the chassis, or if you have to modify the tube and driveshaft...

read this on another buick tech site:

trans adaptor for buick nailhead to 200-r & 700-r trans.$295.00
rod n racin

715 e. main st
bellville,IL 62220
(618)257-0567

I know that my '62 Invicta came with the 2 speed Dynaflow, but whatever's in it now shifts 3 times. We're not talking torque converter lock up here, it is definetly a 3 speed transmission. My suspicion was that it's a TH400, but after reading the posts here it seems that a TH400 probably isn't likely... or is it? The guy I bought it from didn't know a whole lot about the car either, but thought it was a TH400.

The standard column shifter is in place, and whoever put the 3-speed in was smart enough to line up the shift indicator so P, R, N, and D are indicated correctly. Beyond that, there are 2 lower positions (not indicated on the column) that the shift lever will drop into. Of course, the tranny shifts accordingly, D, 2, and 1.

Yes, the motor is definetly a Nailhead. Short of pulling the tranny out, how can I determine what the tranny is?

I know what a TH350 looks like, and have one in my Model A for refernece, but I think the 400 is a totally different animal. Honestly, I haven't even crawled under the old Invicta to look at the tranny, since I've only owned it less than two weeks and work has been too crazy to play with it.

First, I'm curious what 3-speed is going to work behind a Nail, second I want to change the filter and fluid ASAP.

Thanks for your help!

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Eric Hibbs
Southern Utah

'31 Ford Tudor street rod
'60 Chevy Bel-Air
'62 Buick Invicta Wagon

Guys
I've got a 63 401 nailhead, and if anyone is going to make an adapter for a later model trans. put me on the list of potential customers.
Wouldn't think a transmission up-grade would be this hard. I've mostly worked with Fords and Mopars, never had problems like this, my nailhead is going in a '53 Stude, I really like the engine, but didn't think I would have this much trouble.
This is a cool site and thanks for the help and info.
Dale

Thabks for all the info, I didn't know what a can of worms I was opening. I started preliminary work on an adapter when I found an advert in Hemmings Rod and Performance magazine for:

Bendtsen's Transmission Center
13603 Johnson St. NE
Ham Lake, MN 55304
tel: 763.767.4480

They advertise adapters to use chevy 700R4/4L80E/200R4/T350/T400/ P.G. transmissions on '58-'64 Buick Nailheads

If you can use the late model autos with these adapters, presumably you could also use a late model chev 5-sp, or even 4sp muncie, or am I hoping for too much?
Malc

Manual trans adapting is not too difficult. use a stock nailhead bell housing. Re-drill and space for the new trans. if necessary Use a clutch disc with the proper spline and diameter and a throw-out bearing with the correct ID and face diameter.

One more thing to consider, Malc. Nailheads make ALOT of torque, which is very good. They are also usualy in a fairly heavy car. Be sure to use a stout enough manual gearbox or you will be working on the trans quite often. Factory late model 5spd. transmissions are not up to this much grunt. Garage buddy of mine tried a T-5 behind his stock 322 and broke 2 of them before switching to a heavy duty Tremec.

Jeep used the nailhead for awhile with the TH400 tranny. In fact I know a guy that has an adapter for the nailhead/400 boltup. They are not plentiful at all and have no idea where to get them. If you want I will see if he is willing to part with his.

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Here is Pics of the adapters that was used by Jeep for a few years.

http://images.andale.com/f2/116/106/4651773/1034870158797_ADAPTERS.JPG

you can reach him at crazy_jeepman@msn.com