I haven't heard of major heating problems on the 400. Chevy probably made a few million, so I would guess they work just fine, unless there is a malfunction of some sort.

I think you will have trouble buying a lot of HiPo parts for the '09. The supply of parts was drying up when I stopped buying in the late '80s.

The one good thing about the '09, is the fact you will have something unusual under the hood. They ran good, but the bigblock and smallblock Chevies were superior in several ways, so just remeber that Chevy replaced it for a reason.

Problems they had were too much rod angle, causing the pistons to rock in the bore. The pistons were too heavy. Even the HiPo rods were weak compared to the standard 396 rod. They had a habit of yanking the rocker studs, so you'll need to pin those. They had a poor combustion chamber shape, and you'll have to be careful with cam lift if you have the big '62-early'63 heads. I was busting moly push rods regularly, using a Z-11 cam in a '62 motor. The only thing I will say in it's favor was "it didn't run very often, but when it did run, it would leave tire tracks to 100 MPH!"