I was thinking that I could install both lifters without the tie bar and then lift one up high enough to put them both into the slots. Once down on the cam they are OK. No?

I agree they might both be the same height.

By the way, do you think I am concerned about nothing? Will I lose oil up top if the oil hole is exposed? The oil band is also exposed which would seem to cause pumping of the oil out of the band. This is why I thought I needed to bush the lifters.