Mate a STR-8 with a 4-speed OPEN driveshaft

[Guest]

Are you going to have floor change or will it be the old column change?<P>Some where I remember reading that a Ponti open drive shaft gearbox tail section will bolt on to the Buick box (but not sure which years?)

[Jyrki]

We've had discussion before on how to change rear gears to a torque tube rearend, since there's no transmission on earth that will bolt onto a straight-8. I didn't have luck with changing gears, so I mated a BorgWarner Super T-10 4-speed to my 1946 Buick. If you wish to know more, check <A HREF="http://gamma.nic.fi/~marlin/august01.htm" TARGET=_blank>http://gamma.nic.fi/~marlin/august01.htm</A>

[Jyrki]

I will use the Hurst floor shifter that came with the trans, only I fabricated a longer stick from stainless bar stock. I've heard about the Pontiac tailshaft, too, but don't know more about it. I think it was a single statement of someone on the late classicar.com forum. Nobody could ever verify such tailshaft existed, not to mention which years or what mods are needed? I'm not suggesting that anyone else should do what I did, it's just that I know there are many people who insist on keeping the str-8 engine (instead of the ever boring Chevy 350/350 combo), but would like to get better mileage & not kill the engine by overrevving on highway.<BR>Jyrki

[The Old Guy]

Changing to a T-10 wont't change a thing. It is 1-1 in high gear just like your three speed tranny. You will either have to install an overdrive trans or change the rear end ratio to cut the rpm on the highway

[Guest COMPACTBC]

Hey Joe, did you notice that he changed the rear end to an open drive-shaft type he got from an '89 Firebird with 2.73 gears and a posi? <P> Bruce Andren

[The Old Guy]

Bruce, that must be in another post. If he has a 2,73 gear in the rear with a straight 8 he definitely does not need any more . I have a 3.42 in my straight 8 and that is all my engine can handle.

[Jyrki]

I think Bruce went to see my homepage to find out about the rear <BR>Joe, you're correct, but the challenge with the stock trans is the closed driveshaft, so 3.42 is the lowest you could find, or some 3.36 that was optional some year. I think my Roadie 320 cid can handle the 2.73 gear. My 83 Caprice STW weighed more, had a 160 hp 305, and could pull 1500 rpm at 60 mph on highway with 2.73 AND a 0.7 overdrive, no problem. I think the torque is comparable. I'm sure a 2.73 gear MIGHT be a problem with a 3-speed manual trans, since the first gear ratio would be too tall, and shifts too far apart. Now, with the 2.73, I have an added bonus - I don't have to run the tallest bias ply tires to maximise mileage.

[The Old Guy]

The 320 engine should be able to pull that gear. I have a 263 in my Super and the 3.42 is a good choice . you have to watch that you don't get the engine lugging hard enough to open the power circuit as that will kill your mileage. My manual says that the standard 3 speed tranny had a 3.02 to 1 first gear in the small series and a 2.53 to 1 first in the big series. The Borg Warner T-10 had either a 2.54 or a 2.20 first if I remember correctly ,so you won't gain much in the starting gear,but you will have more options after you are rolling

[Jyrki]

The ST-10 came with first gear ratios 2.64 (like mine) to 3.44, while my 46 Roadmaster first gear is 2.39.<BR>The 1957-63 T-10's may have had different ratios, but those were poor gearboxes. That's why GM changed to Muncie in 1964 while Ford introduced Toploader the same year, also to substitute T-10.<BR>The T-10 reappeared in 1975 as the Super T-10. People seem to agree that a Super T-10 and a Muncie are equally strong.<BR>Jyrki

[Jyrki]

That's the way to go, Chrome!<BR>Maybe we ought to establish a new club with a slogan: "say NO to Chevy SB". We could go on with "save our classics from billet parts as well"<BR>

[Guest Chrome]

Hi!<BR>I visited your updated pages and found out that you've added photo of my car there, thank you I appreciate it <P>Your project keeps steady pace, I just garaged my car and it should get interior redone this winter. I bought engine to it also, it's '62 Cadillac 390 and bolts on to my '63 Hydramatic. Now I need driveshaft and rearend and also some minor parts with major trouble (I mean gear change mechanisms etc.)

[Guest]

The Pontiac (or Cad) tailshaft story is a fact. My Dads 1955 Ford F100 had a 1957 634 DynaFlow installed in 1966 and they used a Tailshaft from a Pontiac or something to do the swap. This combo was in the truck until about 1985 when we swapped in a ST400. I will ask my Dad and Brother exactly what it was. I remember it was a long tailshaft that stood out as not matching the rear of the tranny well, but it bolted on.