Hey y'all, the 18rc on my Chinook is real tired. It runs but I'm not really confident taking it on trips with the current motor. It has tons of blow by and compression was around 120 on all cylinders last time I checked. A good friend has a lift, engine hoist, experience etc and is down to hang out and swap in a 20 or 22r with me.

I'm trying to figure out what all I need to throw a 20 or 22r in there. I can live with the 4 speed since I'm not really trying to blast in this little rv.

I've seen some posts say you can just bolt a 22r right in, I've seen others that say you need the motor mounts from a 75 that had a 20r in it.

My understanding is that the frame rails are slightly thinner on these pre 75 trucks. When did it switch over? I'm wondering if 75 is the only year I can use mounts from or if mounts from a 75-78 would work.

I'm trying to get all the parts before hand so we don't pull my motor and then have a dead rv sitting in his garage for months. Any tips are appreciated!