Hello eveyone ive been doing a complete rebuild of my head and i tried to install the lifters on cylinder 1 but they wont go in. Ive got all of the other lifters installed they just slide right in. Ive even tried switching the lifters around but still nothing. Its like the hole is to small but only cylinder 1 exhaust and intake. Should i take the head to the machine shop? Im just not sure on what i should do. I dont know any history of the head it came with the car already separated from the block. Also the lifters im using are from another head but none of them are damaged.

Pretty sure the factory didn't make the bores a different size
But it only takes a tiny nick or burr to make it difficult or near
impossible to get the bucket in the hole. Even when there is no
damage they can be a bi*ch to get in sometimes. So check real
carefully to make sure there is no damage to the top edge of the
bore... just something getting dropped on there during handling
can make a high spot.

Cheers... jondee86

Okay after further inspection I can feel a small lip on the very top of the bores only cylinder one intake side. It catches my finger nail. I got the exhaust side lifters to fit in. So what should I do to make them fit? Should I get like 1000 grit sand paper or a file? I know it's easy to take off aluminum. I just don't want to destroy this head after I've put all this work into it.

If it has a lip all the way round, that would be a problem. But I don't
know how that could happen, so I guess it if just catching in one place.
You can improvise with a piece of fine grit paper wrapped around a
piece of some round material a bit smaller than the bore. You are
only going to be working on the top millimeter of the bore at that
one spot, so angle the "tool" slightly so that it only touches right at
the end of the bore. Work gently back and forwards... look to see if
there is one high spot getting polished. As soon as that disappears...
job done !! Wipe out any dust from your work, oil the bore and slip
that bucket in

Cheers... jondee86

i hate when this happens. luckily its an easy fix.

So I used 300 grit sand paper it didn't take much but the lifters slide right now. Thanks a lot everything looks good to go now.

1st change of oil should flush any residue...

When this happens to me... I don't use a sanding medium, I use a strong bladed short knife. I run the blade around the edge, removing the offending bit of metal in a tiny ribbon. By doing it this way far less "foreign" material gets into the head. And if it falls away, a tiny ribbon is retrievable with a twezzers or forceps.