Would these 2 be related? I.e. Could the crack be causing the low compression?

Truck is a 90 p/u 22re auto 4x4.

My motor bit the dirt so I picked up another truck that was wrecked which had a motor from Toyota 2 yrs prior to me picking it up.

When I went to check out the motor the guy dropped in a battery. Let me know it had been sitting for 4-5 months and if it doesn't crank right away. That's why. Well it fired right up. Spunded great. No valve tick (suprising huh?) so I asked if he could run a compression test just to be sure. He said no problem checked it and compression was from front to back

150-120-150-120 I think that's what it was

Well I talked him down a bit and got the whole truck. Drove it onto a trailer.

I was hoping that with it being a new motor not smoking amd being suprisingly great running it was just a little carbon build up in the valves and a little run time it would be good to go.

Well I got the motor installed and ran it for a few weeks. The motor runs so good. Idles great so I was hoping for great news this afternoon.