Correct engine mount location?

[codyon35s]

Can any of you fellas well versed on this tell me if my 283 is mounted in the factory/correct position? The engine mounts are bolted to the frame at the middle and rear (closest to firewall) holes. 68 suburban with a 283 bolted to a TH350. It gets a little warm if it sits idling for 10 minutes or so in this hot, Louisiana heat so I looked for a remedy. The fan sits about 3-4 inches from the shroud. Thought maybe I had the wrong shroud. After hunting for the right shroud that the fan would partially sit into I had several folks tell me I had the right one (29 1/2"x20"x5 3/4") for my setup. So I dug further. Got to wondering why the 283 in the burb sits back about 4 or 5 inches further than the 307 in my 68 GMC. Then I noticed the other set of holes in the frame. So, should it be bolted to the front and middle frame holes? I've attached a couple pictures and circled the mounting holes I'm talking about.