Stockish 340 upgrades, cam needed

Thanks for the update! And that really puts it into perspective, I’m surprised that they’re only 20ccs extra! You weren’t kidding when you mentioned the low rpm lag in port velocity. Those as cast heads, 9.8:1, and the .506/[email protected] would easily meet goal requirements and then some. If these are the actual heads going on it, I’m not nearly as concerned about exceeding dynamic compression now! What are the port window dimensions there? I’m wanting to calculate at what RPM that much port window actually starts to work at on a 346 inch small block. The .506 lift, 1.6 rockers, and the .903 cam are going to help, it’s going to need the valves opens as quickly as possible just to get that huge column of mixture moving. And are those 2.02/1.63 valves? I’d be surprised if it’s any lower than 3500 rpm... One advantage of the LD340 ( especially if the ports haven’t been touched, hopefully it hasn’t been opened up any) is the reversion dam back into the manifold by the port mismatch and the manifold exit velocity at the flange. Just keeping the mixture in suspension looks like it’s going to be a challenge. I’ve read about a few 10.5:1-11:1 static 91 octane builds with careful tuning, and this is close. 10:1 looks pretty good now more because it will probably take more timing curve than I originally anticipated off of idle. All I can think of when I look at those heads is how well they would work if you could fill the port from the floor 1/3 of the way to the roof. and filling the bottom of the manifold to match.