Magnum 360 heads "best" for my build?

WackoWilly said

A 30 H.P. over stock heads and if you put in 2.02 valves (Int.) better than 340 heads. Their castings just flow better and are new castings. Hughes rocker arms set up is great, low expense and will work if you decide to increase h.p. gains (bigger cam, torque convertor, pistons, carb, etc...)

Click to expand...

30 hp huh?

every 5 cfm in worth 10 hp....

Stock 1.88 j heads w/ a good valve job flow 195cfm-200cfm @28
I have a flow sheet from J&J machine from my 1st set of j's.
They were flowed 189cfm at 25, converted to 28 200cfm

Now stock 2.02 J/X with stock or 3 angle stone valve job went anywhere from 200-205cfm
Same head with a serdi 'multi angle' VJ and new valves[say wide margin valves heads =210-220

the kicker is that there is way more potential left in the older heads.
Magnum heads-cost effective, thin lite castings with low emissions in mind, and the exhaust ports only flow maybe 10cfm more than a j head, as in the shape got better but the port became smaller and restrictive in that lite.

I have actually flowed something before, have you?