Differences in two identical bellhousings

[grants6]

hello i have two identical bellhousings except they each have different size return springs, one is quite a bit larger in diameter, also one has two grease zerts , does anyone noticed this before or am just over thinking this thanks brad in il.

[Brian]

I suspect someone added the grease fittings to it at sometime in it's past.  Never seen one with that before, but definitely a good idea!
As for the spring, the 65 spring was always marginal at best, so I suspicion the larger spring was used on the 66 bell-housings to fix the issue of the one in 65 being marginal.  Definitely go with the larger spring. 

[35chevcoupe]

hello i have two identical bellhousings except they each have different size return springs, one is quite a bit larger in diameter, also one has two grease zerts , does anyone noticed this before or am just over thinking this thanks brad in il.

Hi grants6 , I also have 2 bell housings , one with zerks and one without . I,m sure Brian is correct on this .
I did read somewhere ( don't remember where ) that the zerks were added as a fix to help the throwout bearing shaft to move more freely , possibly to get the release bearing away from the pressure place fingers . It might have been partially due to the lighter spring not moving the release bearing off the pressure plate completely .
The bell housing I have that has the zerk fittings also had the lighter spring in it which was broken .
We did through a few of us here on the site have the springs reproduced in case you need one .

[WkillGS]

The first gen bellhousings had problems with the crosshaft binding up in the housing. Buick modified the shaft by adding some grooves at the ends to retain grease. I think they also added a grease fitting to the welch plug.

The return spring in my 66 was the thicker one, painted green.

Here's the March 1966 Service bulletin about the bellhousing:

[grants6]

thanks for all the responses !

[WkillGS]

>>>do you know of any new parts available to (redo) the housing ?<<<<

The boot that goes over the cross shaft ball lever/yoke is avail from the Buick Farm:
https://www.buickfarm.com/gm-group-0-clutch-engine/1357843/boot-clutch-crosshaft-at-bell-housing-nors
or from them on eBay:
https://www.ebay.com/itm/1965-66-BUICK-GRAN-SPORT-1963-LESABRE-ELECTRA-1963-64-WILDCAT-NORS-CLUTCH-BOOT-/273696132057?oid=273607885891

Other than that, there isn't much available for the bellhousing. The plastic bushing (shown as nylon in above pics) could be fabbed by a machine shop from delrin.
The rubbber washer and seal? Maybe a local plumbing supply or industrial supplier like McMaster Carr would have something close.

Brian had some of the cross shaft 'balls' made up, and Jon (gssizzler) had bushings for the frame mounted z-bar.