Buick Straight 8 manual trans choices...

This weekend a few guys were discussing manual trans choices for late 40's-early 50's Buick straight 8's.

Those selector transmissions are Ok but shifters are pretty rare... what's available to adapt a GM three/four speed to one the old Buick bellhousings?

 

http://www.transmissionadapters.com/Buick_straight_eight_263_320.htm

 

The only GM trans that will bolt to that pattern and not be a just a different version of a GM selector, is the 37 Buick big series top shift trans. Lot of money and work, if you could even find one.

If you have average tools you can build a simple shifter using a big heim joint as the swivel, just like one company did back then. It has a backwards pattern, but will be the easiest shifter to make. real easy

 

Their kit is complete with adapter plates, mini starter, crankshaft adapter, flex plate and all grade 8 bolts. It works with all chevrolet automatics and manual transmissions, new flywheels are also available and come with pilot bushing. I have the kit for my 263 and it is an excellent kit in both fit and finish. In my opinion it was well worth the big bucks it cost.

 

Frank, that's applicable to the big 320 series engines (Century/Roadmaster) , but does not fit the smaller engine (248/263 Special/Super). Looks the same, but different dimensions everywhere, except for the top two bolts.

The previous post recommending Bendtsens is, in my opinion, the best alternative for a choice of modern GM trannys.....stick or automatic.

Ray

 

I was thinking Berndstens kit was auto only... thanks for clarifying that. Lots of other good info on these old selector transmissions, too.

 

Hey kroozer.....

I can attest to the quality of the Bentsen adapter. Helped my buddy put one of their adapters in a '40 Buick with a T-5 adapted to the stock I-8.... everything lined up great! Only thing we had to do was drill and tap the crankshaft to the size bolts that were sent with the kit. I guess they had different choices from the factory.?.?.?

 

I, too, bought a Bendtsens adapter for my Straight 8 Buick, should have mentioned that in my earlier poet, and the quality of the parts is excellent. Not cheap, but quality seldom is. In my opinion, the product is worth the price.


Ray

 

Stick and Dynafow were different... 3/8 vs 7/16 IIRC.... maybe 7/16 vs 1/2"???

 

Bendstens has the crank shaft adapters for both the manual and dynaflow crankshafts, just let them know which you have if you order.

 

Thanks...

 

You can have the bell housing machined to fit a Muncie open up the centering I'D and drill/tap new 1/2-13 holes. Input shaft length is the same. Then you keep all stock clutch linkages etc.

this is for the larger 320 not sure about 248/263

This guy is a genious when it comes to the buick 320
http://www.roadmachine.fi/Buick/Rmaster.html

He did as I mentioned above with greater detail. His site is a great resource. I am building a 40 buick with a 320

 

Will not work on 248/263 bellhousings.......no place to put the bottom bolts on the GM trans pattern. They intersect the bottom edge of the bellhousing and there is insufficient "meat" there to drill and tap.

I have a bellhousing already machined for the front bearing retainer of the later trans, but abandoned the idea in favor of the Bendtsen's adapter for the above reason.

I do think the big 320 bellhousing might be utilized in the fashion you describe, as that transmission has the lower bolts closer to the later GM spacing and the bellhousing/trans mating face is deeper.

Ray

 

I just reread the section in the site I posted and he states he had to weld on some meat and machine flat then drill and tap.

But it is doable

 

I have seen in a post somewhere, a picture showing a extended plate welded or brazed to the bottom of the 248\263 bellhousing, giving enough extension to drill holes for the bottom bolts.

 

Has anyone used the Bendtsen's Adapter on a earlier buick... I have a 1932 57 series that i would love to do a tranny swap on it so it can cruze at highway speeds at lower rpms

 

Do a search for "anyone build there own floor shifter"

 

32 is completely different engine/transmission combination than the later ones. Transmission won't make any difference in highway RPM that's controlled by rear end/tire dia.

 

Unless you get a modern 5 speed with 5th overdrive. But that leaves you wondering about a driveshaft and torque tube.

 

If i can upgrade the transmission to a automatic then i can switch the rear end to a ford 9" and get a better gear ratio.

 

and get rid of the torque tube all together

 

Hi everyone.

I realise this is an old thread but was looking for some information. I have a 1946 Super Sedanette 56S running the original running gear (manual). I'm thinking about converting the car using the Bendtsens adaptor to a modern automatic transmission. I've read a lot of posts on this subject but haven't seen any comments on whether modification to the firewall or floor is required. Can anyone advise me on this that has had experience?

Thanks in advance.

Dean.

 

JonathanW on YouTube made his own adapter to mount a T-5 to a 263 Buick 8 for a Hotrod he built. This is part 1 of 4. Maybe there’s something you can use...

 

Thanks for that. I did watch those videos but prefer an automatic setup. I also have too many projects and have started a new business so don't have the time to do the work myself. My plan is to do the research, and hopefully the new business will make enough money for me to pay someone to get my car going. I have had the car about 7 years, done a lot of work on it, but it's taking too long and I want to drive it. Cheers.

 

I understand "it's taking too long and I want to drive it." I promised myself that the next car/truck I buy will be road ready - no more projects... We'll see.

 

I bought the car in the picture thinking it would be road ready. It turned out to be a real mess. Nothing beats checking a car out for yourself but travelling from New Zealand to Iowa wasn't an option for me. It will be a nice car when I'm finished with it.