Fuel consumption

[Kevin H]

Originally Posted by peter dowdle

Kevin the 400 motors do have different heads and you are right this motor with aluminium head different pistons and cam are very popular with the Hot Rod Boys. The biggest difference between the series one and two 383 motor is they are much higher in compression ( approx 10.2 to 1 ) as against the late 383 motors and the 400 which were about 8.3 to 1 . This leads to about 80 more rated horsepower.

Peter,
I should have said, it's the earlier "906 core" 383 heads that are much more free flowing. However, I have read that if the 400 heads are ported to same as the 906 core 383 heads, the 400 heads will flow just the same, so you don't have to change them!

Wish I had known that about 18 years ago when I bought a pair of 906 core 383 heads.