Heat riser position & blistering paint on intake manifold

[Dakota]

I have been wondering why the engine paint I used on my intake manifold is starting to blister around the carb base.

I have a 340 with stock intake and exhaust manifolds including a heat riser on the passenger side exhaust.   I'm not using gaskets on the exhaust manifolds so the crossover passage is open through the intake manifold.   The car has dual exhaust with no crossover between the two exhaust pipes.

Late last year, the car went into a local hot rod shop for front end alignment, initial state inspection, and a bunch of other items including having them try to address a ticking noise in the engine compartment.  They diagnosed the noise as a leak around the shaft for the butterfly on the heat riser butterfly.  They ended up removing the external spring on the riser and sealing up the hole. The end of the shaft is still visible. I'm away from the car right now so I can't look to see what was used to seal it and what position it was locked, but given the blistering paint I'm wondering if the butterfly is more closed than open.

I'm up to a whopping 650 miles on my rebuilt engine.  I've rarely run it above 3k RPM at this point, but the engine seems to run rougher above that speed.    I have a FiTech EFI but just captured by first data log at low speed with the log feature before I left town for a bit, so I can't comment on those details yet.   The oxygen sensor for the FiTech is on the passenger side.

I get exhaust out of both tailpipes.   Is it the same amount?  Hard to say.

All this leads me to several questions:

Short of pulling the manifold and looking in it, is there a way to see what position it's in by a notch or flat spot on the butterfly shaft?   

How hot should the crossover area under the carb base get?   As I'm typing this, I thought I'd point my infrared thermometer at it, but again I'm not near the car right now.

When looking into the engine bay from the passenger side of the car, does the butterfly rotate clockwise or counter-clockwise to open?  Assuming the shaft isn't welded, I was thinking I could try to rotate it with a pair of vice grips.

Any other help or suggestions would be greatly appreciated.

I found a post in this forum from 2017 here where several members commented about how they wouldn't want to have a heat riser.  Add me to the list.  Once upon a time, I was going to keep my car looking as stock as possible but I think that plan is fading fast.

[Racer57]

Odds are the shaft is permanently  rusted into its position. If you ever have the manifold off, you can remove the flap (if its still there) with a torch or saw. Also, you can buy intake gaskets that block  off the heat ducts going to the intake which will help with the paint burning off.  You do not need them.

[Dakota]

How this for a bad case of CRS (Can't Remember uh  Stuff)?

Part of my original post above asked about the heat riser rotation direction.   Back in 2018, I provided the answer to the same question asked by another member about the rotation direction for the heat riser valve (it's a clockwise rotation to open when facing the manifold).

https://forum.e-bodies.org/exhaust/17/340-heat-riser-valve-how-to-jerry-rig/8131/