The .904" MoPar lifter may work, but the pushrod ball diameter and the height of the pushrod cup in the tappet (not the overall tappet height) may require a different pushrod entirely.
A common sleeve material is 660 bronze, available as hollow “cored rounds” in common fractional sizes. 1” OD × ¾” ID can be bought in a single length, reduced to .9905” etc. OD for a light press fit, reamed for clearance to suit the tappet body, and sawed into 12 individual bushings. The bushings require holes through both sides to permit oil pressure to transfer across each tappet bore.
I don't know if the wall thickness (.990" - .904" = .086", ÷ 2 = .041") is enough for safety. The smaller .875" (Ford) or .842" (GM) tappet may be a better choice.
Another factor is the height of the oil supply groove - will it line up with the Chevrolet supply gallery? The tappet body must seal your hydraulic lifter gallery during the entire lift range, and the feed port must be inside the gallery and exposed to pressure much of the time.
This is precision work, especially the alignment of the sleeve, except to pay accordingly.
