ALERT!! SOUND THE ALARM!!..

What do you mean you can't use "that flow" at the moment?

That doesn't make any sense to me.

Sorry, didn't mean to confuse anyone.
Going on an stock-ish 340 street car. The cam and intake system can't make use of the extra flow that would be available at higher lifts from the big port/valve Shocker 185. So it doesn't make a lot of sense to spend $1000 bucks now for performance that will not manifest itself until a new motor is put together. Sorta like putting a set of TF or W2's on a 340/360 but not changing anything else, it should make more power, but there is going to be a lot more head than the engine can use.
The 171 version flows same or a little better than the Edelbrock heads and that will be a good improvement from the J-heads and still be balanced.