Sure they made them in aluminum.
'70 and up big blocks had them, but they were for the 10 1/2'' clutches with 130 tooth flywheel and had a 4.807'' opening for the bearing retainer.
2892513 is the number for them.
Have you or anyone you know used the Lakewood aluminum bell housing you listed?
I was wondering about fitment etc. as I'm sure the O.P. and others would be interested in this info.
That's a good price for them as well...
I had an OEM bell in a 70 roadrunner in about 78. We were driving down the road when all at once the shifter rotated around and like to beat the hell out of me. The bellhousing had split radially all the way around it.
I bought a gTx at one point with an aluminum bell in it and noticed it was cracking. I paid a guy to TIG the crack, and when it came back it was so warped that it didn't fit the back of the block any more. It should have been bolted to a block, and maybe a transmission, before welding. It's now wall art.
In both cases the crack started where the dust cover mounts up.
If you use one of those OEM bells, look at it carefully and inspect it often.