98 RON is about equal to 93-94 in the US, so I'd stick with 9.5-1 or so CR. I have seen higher run on that gas, but I like to make errors on the caution side.

If i am undersrtood right, the dynamic compression ratio should be arround 8.0 or bit more.

you can go 10/10.5-1 compression.I ran 10.3-1 for years on iron heads and 93 octane.

In very general terms, yes. Big difference between Dynamic and static CR.

Just bought Summit brand 308cc rec-port heads. Used under 20 hours. could be same as Dart iron eagle 308cchttps://cimg5.ibsrv.net/gimg/www.off...3468dccb7d.jpg
https://cimg0.ibsrv.net/gimg/www.off...1ceb2de261.jpg
https://cimg5.ibsrv.net/gimg/www.off...d4b5b46a03.jpg
https://cimg1.ibsrv.net/gimg/www.off...d031cc3377.jpg

summit brand cast iron BBC is from Dart,

the 308's need 4 different cam lobes. :bunnydance::lolhit:

very good choice,one million times better than the peanut port gm head.

You just made your goal a million times easier to reach.

This intake came with the heads. Cant find any casting numbers.https://cimg7.ibsrv.net/gimg/www.off...b41107c12c.jpg
https://cimg2.ibsrv.net/gimg/www.off...6685279fec.jpg

Not sure if it's ok to post this
but if any problems with your big block?I have 2 new 454 HO rectangular port one with new intake & stainless marine exaust!Sorry for the hi jack!