[JC455]

Hi all,
I pulled the 215 6 cyl./3 speed manual and dropped a 350/TH350 in the 64 Tempest.
I just acquired a Dearborn 3 speed, so I'd like to change it back to a manual trans...
Is anything cross-compatible between the 6 and the Poncho mill? I'm guessing the frame-mounted bracket that holds the Z-bar's outer stud is the same... I'm wondering about the Z-bar, the upper and lower clutch rods, outer Z-bar stud, etc.??
Thanks for any help!

[Stuckinda60s]

I did a 400 swap into an 81 GMC that came with a 250-I6, I'm not sure, but I think I used the same Z-bar (along with everything else, including the low mileage 250 disc/pressure plate). I think I also used the throw-out bearing with the pressure plate, but I'm not sure. You do have to be careful with your disc/pressure plate/ bearing combination because the Chevy used a thinner pressure plate with a longer bearing while Pontiac used the opposite. The Pontiac design is far superior, Chevies had a bad habit of having the clutch stick to the floor when power-shifting. They went over center because the diaphragm springs were so short.

Obviously,I had a different year and chassis than you, but the engine to engine swap would be more apt to fit in your car that came with Pontiac V-8 options than my truck. I think everything will fit, but I'm not absolutely certain. All I can truthfully say is that it was an easy swap with no teething problems once done. One thing you need to check before you get too far into it, is that your crank is drilled for a bushing or bearing, not all engines with an automatic code did.

[John V.]

The frame mounted bracket should be the same I think. It is welded on and I can't see any reason why it would have needed to be in a different location for the 6 cyl. I seem to recall a thread that discussed the location of the tab and may have included pix. If you can find that thread you could compare with the location of your tab just to be sure.

The Master Parts Catalog lists different p/ns for the '64 T8 vs. '64 T6 for the Z bar, (the T8 is called the "Clutch Control Countershaft", the T6 version is called the "Clutch Lever & Shaft").

There are also different p/ns for the clutch release forks, the T8 had a PMD p/n, the T6 used a Chevy p/n.

From the illustration, there are many differences in how the clutch fork connected to the Z bar as well, different clutch fork push rods, different return spring arrangements.

The clutch pedal assembly was the same but different p/ns are listed for the clutch pedal to Z bar push rod, presumably because of the Z bar difference.

However, in comparing the illustrations, I can't really tell if the T6 set-up could work with the V8.

Would have to compare the width of the Z bars, the distance between the clutch forks and the Z bars, etc. The '64 T6 used a two piece clutch fork push rod for adjustment, the T8 clutch fork pushrod was a single piece.

One clue that the '64 T6 set-up could work is that it seems the '66 T8 set-up was revised to the T6 style with the same p/ns used for the two piece clutch fork push rod as for '64. But new p/ns were issued for some of the other '66 components (and the T6 was now the OHC6 rather than the Chevy design used in '64/'65) so I can't be real sure.

The stud ball on the engine was same.

I'd say go for it. Worst that could happen is you would need to replace something to make it fit.

Rich made a very good tip about the crank.

As to the clutch, there was a standard '64 T6 clutch, a 10" HD T6 clutch, and the 10.4" V8 clutch.

Flywheels carried different p/ns for the T6 and T8. No idea what differed except for the bolt holes for the pressure plate.

I don't think the bellhousings interchange.

[JC455]

Thank you, guys!
That's interesting about the 66 info....
The flywheels and bells won't interchange- Pontiac vs. Chevy
Good point about the crank being drilled!