I'm trying to confirm that a 1971 GS is a true Stage 1 or at least a GS 455 - not getting very far with the Stage 1 issue but would the manual transmission be different for a big block vs a small block? If so I could at least confirm the car is a GS 455 but not a Stage 1. Thanks Greg ________ Easy Vape Reviews
For a 70 just as an example I see no differences in either the assembly manual or the parts books. Post a pic od the steering shaft at the flange around the rag joint and let us take a look.
Is it an original Stage 1 or clone? If original, the engine code should be TS located on the deck of the block between the #5 & #7 spark plugs. Check out this web page for more info.
The original engine is long gone replaced with a 72 GS 455 block so without documentation all I see is potentially a cloned GS 350. Thanks Greg ________ PREGNANT TUBES
The z-bar and linkage should be different for a BB car, unless that's been changed too. Otherwise I thought there was a number stamped in the Frame somewhere on the rear drivers side of the frame that would tell you if it was a 350 or 455 car. The other tell tale sign is the sterring shaft coupler.
Thanks, the column looks to be blue so on a cinnamon car I would imagine its been changed. Where would I look relative to the z-bar? ________ Tacuma
To determine if it is a BB car would the first few numbers of the Vin denote it is a GS 455. I know 70 does, but not sure of 71.
Hey Greg, The big block car has a shift fork that uses a heim joint push rod, ie" the push rod has a bushing in it and it is held to the fork using a pin. I believe that on the small block fork, the push rod sits in a depression in the fork and is held in by preload on the linkage. ala Chevrolet. I seem to remember seeing pics somewhere on the site awhile ago. Hope this helps Adam
If its a small block 4 speed, the input shaft will be coarse spline (1 1/8x10). The big block cars used a fine spline (1 1/8x26). Also, small blocks use a 10 1/2" disc while big blocks use an 11"
Not so in 73 though...My 73 GS has a M21 fine spline(26) in it an if I were a betting man...I bet some came that way in the 70-72 cars.I also have a matching number trany(M20) out of my 68 GS400 (coarse spline)I would say that finding the frame numbers will be your only chance to prove authenticity.
Thats interesting Pat. The trans from my 73 Stage 1 was also fine spline. And the small block 73 I had was coarse spline. I had found a definite pattern over the years with it. But, if its like everything else on these cars, its whatever they had available got put in them. Another mystery to solve...
Phil On a 71 the same convention is not used and the GS 350 and GS455 used the same 2 digit code. So you cannot tell from a 71 VIN.
The lower steering shaft flange where it attaches to the steering box is different between big block cars and small block cars. On a big block car, the flange is cast. There is a 12 point bolt that tightens the cast pice to the splined steering shaft. On a small block, the flange is stamped steel. Its just one thing to look at when your trying to determine if a 71 GS was a BB or SB originally. Another way is the gas pedal if its an automatic. On a BB, the gas pedal will have the T-400 kickdown switch. Big blocks also used different tranny crossmembers. All little pieces to the puzzle
Here is a BB shaft. Note the 12 point bolt. Next time I sell one of these, im going to say it fits a BB Chevelle instead. Looks like advertising it that way is worth another 100 bucks :error:
