Cool stuff Heo!  Yes it is shocking when I look at a 25 year old car now vs when I was a kid in the 70's. 

The late 90's cars still look pretty modern and a lot of them are on the road.  In the 70's you wouldn't see any late 40's or early 50's stuff on the road.  They were so old fashioned and archaic!

If you just need to deburr the bottom of the hole, a hand tool like this could work.  The triangular cutter pivots so you can slip it down the bore, then flips out underneath.  You need to check the size of the tool vs. the lifter bore:

https://www.amazon.com/NOGA-Reversible-Tool-Holder-Set/dp/B002NERHN4

I just stumbled upon a great-looking wood boat build with twin 500+ inch FE power!

From Van Dam Boats' Website:

You're a good man Heo!  (... and I don't just mean your taste in hats  ) 

I think that's an old horizontal band saw.  Great tool to have for cutting stock!  Good on you for helping the guy out with his 350 

A nice 58 Impala.  Who can guess what car is behind the Impala?

Oh man that was a hard one!  1960 Opel Kapitan.  I knew it had to be German or eastern European from the Mercedes 220 styling...

Heo - The shadow of the big hat on the Galaxie's fender would have been enough for me!

Enjoy that fine refreshing beverage 

You may need to pull the intake and check the coolant passages.  Since that's the one major part you changed, I would be very suspicious.  There could be a big chunk of slag in there.

See Heo - We have hats over here too!

Here's an old girlfriend from 25 years ago in my old Galaxie.  The picture hides her impressive assets..     I'm talking about that sweet 390 with low riser heads, CJ carb, and four-speed, of course! 



This is me around the same time.  Just getting ready to move to California.



Roll back another ten years and I'm in the small block Ford world.  Restoring the first car I bought, a '68 GT 350.  Man I wish I had kept that car 



Here's the car pretty much done, before stripes.  It was Highland Green:



Edit:  We always had Fords growing up.  Here I am (left) with my dad and little brother around 1970.