Anyone have desktop dyno be willing to get me a ballpark?

the user manual states the rule of thumb is that 95-105% of the exhaust valve diameter is considered a small tube header

120-140% of exhaust valve diameter is considered as large tube header.

It states that any mufflers simulated are high performance mufflers.

measure the actual compression ratio of a smog era 360, if it's over 9:1 I'll eat my hat, your hat and everyone else's hat.

I always think it's amusing that all the magazine articles tend to encourage everyone to think that an engine can be made into a 400hp+ fire breathing monster by bolting on an intake, some headers and a baby hydraulic cam, as if horsepower comes in chunks of 50 at a time with every mod.

You may have gained 2hp peak by going to a smaller bore, but the average would have been shot to hell because of the lower displacement.