Stage 2 exhaust ports

Proper cross section through out the entire port means far more than flow numbers.In a perfect world the valve throat should be the smallest part of the port.Now this will all be set by cubic inch and rpm.
Improper short turn shape will murder a port as will valve job and how it blends into the chamber.
Valve size on max effort stuff is crucial.Imo you need the biggest intake valve you can get but once again cid and rpm will dictate this also.I wouldn't get to worked up about exhaust valve size with in reason.You can manipulate a bad exhaust port with cam timing.A bad intake port is a bad port.
Our old nmcs xs 525 bbc had a 2.420in and 1.75 ex valves.it made 1080 na but at times sprayed over 700 hp nitrous at it.This was with a 2-2.125-2.25 step header with a 4.5 collector.
Back to the buick stuff we don't a cylinder head with valve spacing to allow a big enough intake valve and of course the port to back up the valve.
All in all what the hardcore buick community has done hp wise is quite impressive with the limitations you have.

 

Or start with a raw head and move things around. Yes about the intake valve.

 

Need to send a head or blueprint off the MBE and a blank cheque lol

 

It definitely takes the right place or person. My Buick heads did not start out as raw bricks,unfortunately,but bare castings. Everything was moved. Valves,pushrods,ports. Lots of welding,matching,epoxy,and custom parts.
My Oldsmobile heads did start out as raw bricks that allowed things to moved around initially,without all the welding. Same situation. It takes the right person. There is currently a young man,a son of a friend,who has a deep passion for this and is developing some amazing things. One of which is a billet head. This kid gets it and is making great strides. He loves a great challenge and his products are spot-on amazing.

 

I would say for back then.it had more to do with the then new high swirl combustion champ we.
Probably a combination

 

The "old school" formula of "if a little bit is good, and more is better, then too much is about right", seldom yields the results expected.

 

We have an oven in our shop specifically used for repairing cracked and damaged exhaust manifolds and cylinders heads. It works exceptionally well. We took a pair of 1231786 castings and put them in the oven until they reach 1400 degrees and sometimes glowing red. Then there is material welded to the head to reconfigure the ports. The heads have to be wrapped in a special blanket to cool down gradually over a period of 24 hours. For the welds to cure properly. Then because of the process the heads have to be hot tanked and checked for cracks. All new guides and resurfacing are needed. Because of the high heat process. Then the porting work is done by brother Duane. And the results produced 70 Iron Castings flowing similar to out of the box TA Stage 2 SE heads . Ken Montour's ALL IRON STAGE 1 464 " ended up running 9:80 all day long a best of 9:75 ET with these heads. See the picture of the464" engine at the end of the video. Engine was cranking out 800 HP

9 Second 1970 Buick GS Stage1 Iron Head Update 9.75 @ 133.61 - YouTube