I’d concur
I also don’t like the mild 353 lift
I think this head might touch 200 intake but it’s useless because I can’t swing the valve open that far using this cam
I’ve made roughly 25/30 hits on the bench
What I find interesting is unshrouding the chamber did not help at all on the intake flow
I notice flow flattens at .350" lift mostly anyways. I see this with most Enfields. The port flattens the flow at higher lifts. All the Bullets are also like that.
After your porting, the flow goes a little more up at .400" which is a benefit, but the cam can't use it.
Our experience shows these ports can benefit from raised roof. And with a port entry size 1.125" x 1.060" with a 432.5cc cylinder volume 33% larger than stock, the port is going to have to flow a lot more air thru that relatively small size which means velocity will be high. As rpms increase, it is probably going to start choking well before you get to redline and that will affect cylinder filling.. Normally, this can be somewhat made up by later intake valve closing, but we don't have that with this cam.
So, I recommend checking velocity, keep it under 400, and it will probably need more cross-sectional area in the port and intake tract. I think it will need to be equivalent to 1.125" round area, at least. When we did the 700(stroked to 750)Super Meteor twin heads, we used 32mm(1.25") ports and carbs.
I don't like to make it too big or it loses lower rpm torque, but it does need to be enough.
Our best results came from raising the roof.
Check it for yourself and see what you think it needs.