There is going to be lots of room for improvement.
When I pulled the exhaust manifolds, look what I found. In case
you haven't memorized Fel-Pro's inventory, 1419 is the exhaust gasket
for regular heads, NOT CJ HEADS. Notice how much of the gasket was
inside the port's opening.
Exhaust port left side / floor / ceiling
Before
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After
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 |
 |
- The port was widened and the head bolt hump has been ground flat creating
an almost flat, straight shot from port exit into the bowl, there is just a slight
curve remaining. Although I tried to measure and cut all ports the same, at
1.5" wide two of the ports opened up into the head bolts. This is
SUPPOSED to be OK.
- The thermactor boss and hump are gone now.
- The port floor is filled flush with the short radius turn using Cotronics
954.
- Although I don't show it in any pictures, the bowl / throat transition and
and the short radius turn received standard treatment.
Exhaust port right side / floor / ceiling
Before
|
After
|
 |
 |
- The slight lip on the right side of the port exit is removed.
- The vertical ridge is completely removed.
- And the port is widened to
1.5".
- Here's another look at the port floor fill.
- The slight lip at exit from the short radius turn / port floor / right
wall was smoothed
down quite a bit, but I was afraid to take it away completely in case water
is close underneath.
- I reshaped the exit from the top of the bowl to the port ceiling. After
removing the thermactor hump the transition from the bowl to port ceiling
was a bumpy mess. Basically the port was much higher than the bowl
exit and then came down and then angled back up. (If you are porting
these heads look closely at this part of the head before you completely
remove the thermactor hump. I am CERTAIN if I had it to do over I
would have not removed as much material.) I used the Cotronics fill to
make a flat, straight exit from bowl to port exit. The port
cross-section still expands as it exits because the floor is flat and the
ceiling angles up.
