smog ports on exhaust manifold

For now, I'm going to use the stock exhaust manifold on our newly built 6cyl 250. The thing's a 1975 250 and have all the smog BS fittings.
I was just going to put a bolt in the holes and call it good, but 3&4 wouldn't come out.
So I had all of them welded up from the outside.
Now the inside is what have have question about.
Take a look at the pictures and let me know what I can use to fill the inside part of the hole. If it's really needed. I know the smoother the better.
JB Weld, some other high temp filler.

Before you get started on telling me I should of just gone with headers, or go to a junk yard and grab another year exhaust, here's the deal. It's my girlfriends car, which just a quick engine swap has turned into more $$$$$ than expected.
At this time I just want to get it started, break in the cam, and get it on the road. Then we'll do the exhaust later.

Looking at 3,4 from inside


I know it's ugly, but it will do

 

Why Bother to SMOOTH 'em?
That would be a waste of time & effort Slick.
Just like writing this.

 

Run it.

The engine won't know the difference, neither will your girl.

 

yea, run it......you've already blocked the outside from leaking. i used plugs on sbc motors that had the injection tubes and never had a problem.

 

This was my thought, but........
I've heard others say to "waist" your time grinding and smoothing, and making the surface polished.

WTF, it's exhaust......... get that shit out and make room for the next stroke.

Thanks

 

If I were concerned about the inside, I'd just weld them up like the outside. I do like to grind the flashing and ugly blobs off of cast iron manifolds. I just like them detailed.