Wondering if the idle screw should be capable of completely closing off the air bleed. I noticed today that when mine is screwed All the way in it still allows air through the channel. If I put my thumb over the channel the idle drops another 200 rpm.

I think that's pretty typical, either because it's worn or just not machined such that it doesn't completely close. At least that's the case on my original high mileage '75 TB and another NOS '73 throttle body I bought a while back.

I keep planning to modify mine so it fully seals, but haven't gotten around to it yet.

I would like to do that as well. Any idea what massaging would allow it to seal?

I made the mistake of cleaning it and now it is worse ....

When I fully close my bleed screw the engine dies.

Thats the way it should be, the engine should die with no intake aire source. Otherwise you have a free air leak somewhere in the intake that overrides the air bleed screw function.

Yeah, if I thumb over the bleed port and the hole in the butterfly, the engine dies.

So i take it my condition is not 'stock' then. I would like to fix this....

The leak is from the bleed screw port. For some at least, screwing it in all the way doesn’t fully seal it.

Plugged it with some hot glue gun action...

Held up nicely 2 hours on the freeway and 10 pulls at the Dyno. Can recommend.

Anyone have a link to the business that rebuilds the throttle body? I tried searching but nothing came up.

This guy rebuilds them - Phil

Thanks! Winter is coming....