Yes and no and here’s why. If you take a stock valve out and there is no improvement, then what is under the valve was the restriction. I haven’t gone slower in doing that alone. When I was a young man, I had 2.02’s replace the 1.88’s and I went faster without the work behind the valve to really take advantage of it.
Now if you take a 318 heads 1.78 valve out and use a 2.02, I’d bet the change doesn’t yield any track results worth reporting as a positive move since under the valve wasn’t addressed. But I don’t know that for sure, but I’d bet on it. The area under the valve is very small. A larger valve in this case (IMO) without bowl work really won’t help. Again, IMO.
The problem here is I have never met anyone that has replaced a 1.78 valve in a 318 head with a 2/02 much less port it afterwards. Right here at the forum, anybody that has been around the block a few times will advocate the upgraded work for a 318 but no one will do it.
Often I have said use a 1.88 in 318 head and work the bowl since the build isn’t much of a leap from stock. It’s hard to convince people of what works and what doesn’t even though fellas like Richard Holdner have dyno proven this more than a dozen times himself.
Everything is relative.
A head guy I know has a 1.94 intake valve 10 to 1 Nova at 3200-3300 pounds running 9.80’s wheels up with the factory iron heads on it in S/S.
He swears on small hole, torque and velocity in everything he does.
And to say he is well respected is an understatement.
This guy is a special case and I wouldn’t apply this to the average build. His thinking is sound and I’m not going to argue the merits of his route. Like it was said above, if he did t NEED to run that head, he would not run that head. The class forces the use of a stock head (correct?) and that forces OOTB thinking.
I certainly give him credit! But most here and in the world aren’t building what he is doing.