1970 3963512 Block Strange One

[nuch_ss396]

Joe,

The use of a 4-bolt block in place of a 2-bolt block is
one thing. However, I'd like to know if this engine in
question had a '6223 crank, dimpled rods, etc.. Also, of
particular interest would be the piston domes. Rectangular
port heads have larger combustion chamber volumes than
those of the oval port heads ( 107cc's vs. 101cc's ).
SHP piston domes are considerably higher, so I suspect they
wouldn't fit in the oval port heads properly. Can you find
out more about the rods & pistons? I'd like to know
more.

Knowing what we know today, I'm not at all surprised at a
finding like this. If they needed a block to make production
and a 2-bolt version wasn't available, they took what they
could find.

[nuch_ss396]

Come to think of it, I remember seeing something in the past
about the 1966 big blocks. I believe some 360hp 396 engines
used 4-bolt blocks in some cases and GM sent a service bulletin
to dealers alerting them to the fact that the piston domes
were different and that care should be taken when replacing
the short block assemblies as the SHP pistons would interfere
with the oval port top ends.

Anybody remember this? It may have been in Colvin's books.