I finally started removing the head today, and ran into the problem of keeping the chain tensioner on the timing chain when I remove the chain from the cam gear. The Haynes manual mentions a tool or a block of wood, but this is unclear to me. Can someone detail what needs to be done before I unbolt the gear.
I checked compression before I started and 1&2 had 170 lbs, 3 had 125, & 4 had 50. I'm hoping I only need a head gasket, but from what I see in other posts, a cracked head is likely.

Thanks