valves

[country50]

Going to go 9.5 compression and run EV 27 cam . Know I can run heads stock but was wondering what size valve change would help most . Also changing solid lifters back to hydraulic . Have Velva Touch setup going to be using . Hence the EV cam .

[Hillside Motorcycle]

The OEM Shovel valves are already plenty big.
Not much you can do in that area shy of a good valve job.
Welding/re-shaping the intake short side can help quite a bit.

[Burnout]

Are you also running EVO rockers?

There is a ratio difference.

[country50]

yes going to evo rocker arms

[Hillside Motorcycle]

That cam will want the Evo lifter roller also.

[Wiseguy]

You can gain some flow by building up the intake port floors to get the air to turn down to the valve head easier. Welding is laborious, expensive, and the heat can distort the aluminum holding the seat to let it loosen if the welding gets too close.
I had Cyclerama in Pinellas Park Florida flow my S&S heads about twelve years ago, and they built up the intake port floors with epoxy. It came loose in the rear intake a couple years later, but it went through and out the pipe without damage.
Mike from Sorenson Performance told me about an epoxy that Edelbrock uses to test their intake ports for dyno work, and it stays put.
I prepped it by drilling a series of 1/8" holes, 1/8" deep and 3/16" apart to give the epoxy something to grab. It stayed in the heads for the six years I had the heads after the mods, when I sold them. Last year. I haven't heard anything from the new owner of the heads about any epoxy problems.

[Hillside Motorcycle]

Epoxy should NOT be used, only in flow testing, exactly for the reasons already sited.
Welding of the short side, and close attention while up on the flow bench, is the answer for those wanting to spend the money.