ALL Aluminum blocks grow period. This affects rods,mains cam bearings, pistons and rods. Most error on the safe side for things like piston to head etc. The also loose heat very very quickly. Building cylinder pressure is another issue because they loose heat so fast. Most would be very surprised the compression ratios run in really good running stuff with an aluminum block. In general you need to ad compression if you are going from a steel to aluminum block.

We run a LOT of compression ratio in my stuff and the Vette. On the reverse side you can run a fair amount of compression in an aluminum block on pump gas. We have done a few in the 12.5 CR area and no issues.

Been a huge issue with OEMs starting 60 years ago with the Buick V8. The OEM guys do all sorts of weird stuff such as spraying iron on the cylinder walls rather than using sleeves.

The 13/14 GT500 motors had that process, same with the Coyotes - aluminum block with a spray coating on the bores. Aluminum jug dirtbikes are similar too, some are sleeved but many are coated. There is a ton of work in the design of a modern aluminum block, and the RB block has bigger mains, bores and 1-2" taller deck height than a coyote or LS, so there is more growth for a given temp compared to a smallblock. I don't know of any modern big blocks from the factory with aluminum, the GM 632 crate motor would've been a great opportunity and GM decided to make that one in cast iron.

Al, have you come up with any amount of compression increase needed to offset the effects of an aluminum block? I calculate compression by figuring in the block deck increase due to heat. My cold piston to head is .040, and use +.010 added to below deck measurements cold, since that is where it will be under load. But i doubt that will also account for rapid heat loss due to the block being aluminum, which will reduce power output more..

Al, What is your opinion on compression for a pump gas street motor vs. an 8-second drag motor, aluminum block that is ?
Maybe 11:1 on 91 octane ?

We never pinned cam bearing in a world/BMP block, use green Loctite and make sure cam fits and turn easy with oil on bearings. We always spray Cometic head gaskets with copper spray and sealer around water passages. The rear/main water passage in the BMP deck was to small , so I machined them bigger . I align honed the main bore to the small side of the spec and ran .003-.0035 main bearing clearance with MS 1795V Bearings . Piston to head .040 with steel rods , we seen contact at .037 . That was with iron block back in the day , Aluminum will grow so we ran the compression higher . Use a compression sheet and play with piston to deck to see what the change will be, Diamond had a nice one I always used. No one will pay for R&D so you have to make the best call on your build and go over everything with a fine tooth comb .