340 main bearings

Hello everyone, my name is Eryn Pennell and I was hoping I could get some clarification on my 340. This is my first post so go easy on me.

I inherited my dad’s 66 valiant 340 and am in the process or rebuilding a new 340. Ive never built a 340, but have built a few engines before.

While taking the engine in the car apart I noticed there are upper main bearings on both sides of the crank in #1, 2, 4, 5. The only lower bearing was #3 thrust. Is that normal for these motors?

Thanks!
EP