[storm9c1]

Hard to tell with just a few random pictures and partial angles. So I'm not even going to make a judgment there. At first glance though, I see nothing majorly wrong or anything. I'd need to see (and feel) that stuff in person and check things with proper tools (looks can be deceiving). I'm sure the machine shop will give it a good go etc. Your logic sounds reasonable with your options and workflow. And I agree, be sure to consider cam carefully into your equation, especially with your target CR. Stock L29 heads should be 119cc. If you go with your 148s (3933148) they are 122cc or 112cc (conflicting info about them online and my books don't have the volume). My book says '69 396 passenger car oval port 2bc. And then 68-84 366,427 tall deck HD truck, oval port.

FWIW, you can also buy new GM performance heads that are 99cc IIRC.

Sounds like it will be a nice streetable setup with the NV4500 if you are still going with that. Keep us posted.