I think you may have misunderstood me.
I did not mean just a V8 driving a compressor air end.
I was going to remove one V8 head completely, and fit a very thick piece of angle to make a hybrid.
The upright of the angle would bolt against the manifold to block that side off.
Fit 4 inlet and outlet flapper valves to each chamber .
Somehow keep that side hydraulic lifters in place or have zero oil pressure.
One bank is 4 cylinder power, the other bank is 4 cylinder compressor.
But a 289 firing order is 1-5-4-2-6-3-7-8, so it can't be done.
Would not run too good.