5.7 Vortec to 4 speed

[KJSR]

I had this posted in another section but thought it may get more traction here. I know I’m not reinventing the wheel here but I can’t figure out what I’m missing. I have a 1964 C10 with the factory 4 speed. It originally came with a 230 which I replaced with a 5.7 from a 99 Chevy truck. Everything went together fine but I could not get the clutch to work correctly. The disc does not seem to be disengaging. Here is what has been done:

• Engine was built using a stock flywheel and clutch from a 99 Chevy truck. The original throw out bearing from the 64 was used.
• During the initial engine start the clutch issue was discovered. I was unsure of the linkage and the amount of movement the arm required to disengage the 99 clutch properly. I modified the clutch arm to have extended movement at the clutch fork. I am utilizing the inside linkage hole on the fork. The new set up stopped about 4 inches from the floor so I was confident that I was getting full travel. Still wont disengage.
• I read some threads about similar issues. I discovered I had the “short” throw out bearing so I replaced it with the “long” throw out bearing. I also checked the disc to ensure it was installed correctly. Reassembled and re-tested, still wont disengage.
• I have ordered another pressure plate but am not confident that is the issue. I am becoming very proficient at pulling the trans out!

I’m sure someone out there has done this change and had it work. What the heck am I missing? The only other thing I could think of is the throw out bearing snout is too long and pushing into to the disc. With that said there is no smoking gun (signs of wear or other carnage). Any thoughts or experience with my issue? Thanks for your help.

[geezer#99]

Did you know starting dual threads is a no no.
You can ask a mod to move them though.
This one might get deleted.

[KJSR]

Thanks geezer. I had the other deleted.

Thanks Liz for the help!

[1963c-10]

Not that it makes much difference, but what bellhousing are you using? Is it the factory frame mount bellhousing?

[cru_zn_29]

Could the clutch plate be in backward ?

[tincan1966]

Why not just use the original clutch setup for the 230, using the flywheel from the new engine?

[KJSR]

Thanks for the replies.

I am using the original 6cyl bell housing, with the mounts.

The original clutch is a different si\ze than the 99 and I cant remember for sure but I thought it was a different bolt pattern. When both clutches were installed (6cyl vs Vortec) the installed height was about .010 difference which shouldn't make a difference??

The disc was verified to be installed correctly.

Has anyone ever had to shorten the TO bearing snout before??

[geezer#99]

If it won't disengage why would you want to shorten the tob. And how would you be able to? It's a bearing.

[KJSR]

When I was saying snout I was refering to the guide sleeve the bearing rides on not the actual bearing. I think it may be in contact with the disc.

[geezer#99]

Out of curiousity how much freeplay do you have between the tob and the fingers on the pressure plate?
And I don't see how the edge of the bearing can ever get near the fingers.

[AcampoDave]

Is it the diaphram pressure plate or the one with the 3 levers on it?

[Captainfab]

The one time that I had a clutch that would not disengage, the disc was in backwards.

I don't see how the front bearing retainer could affect the clutch disengagement.

My son's '63 K10 has a Vortec 350 bolted up to an original style bellhousing and a SM465 trans. He has not had any clutch disengagement issues. I believe the front bearing retainer on the SM465 is the same length as the front bearing retainer on a SM420.

[KJSR]

Thanks Captain Fab. I messed with it last night and found the clutch disc is binding on the input shaft. I hope to have this thing done this weekend. Thanks for all the input.