Bowtie block ?

I have a chance to buy 2 blocks they are new in the crate but been stored for several years. Block #1 is a 182 casting that does not have siamese cylinders gm says max bore is 4.030. I was told that it would go 4.060 with no problems is that true? Also it has 2 bolt mains again I was told that gm done this so that the builder could put splayed caps on is this true? Will this block handle 650 hp?
Block # 2 is a 184 with 2 bolt mains did GM change or update anything on the 184 that I should look for? Both blocks were bought from Hendrick Motorsports several years ago

The blocks come with two bolt mains because G.M. uses the main bores as a reference in there machining operation. they aren't intended to run like that and need to have 4 bolt caps installed. either block will easily handle the power level you want. Bill

Just make sure they weren't cast for some kind of experimental purposes. There was quite a bit of that stuff made for R&D work and then sold off when it had flaws.