question about intake manifolds

[aknight_sa]

good day guys,

when i read threw the specs of intakes.. some say they are oval port and some are rectengular port... what is the difference between them? and which is better for the street/strip application?

i have a 1986 BBC engine...which type does it have??

thanks

 

[Thunder]

There are 3 types of BBC heads.
Rectangular port= high performance heads= Good for high performance/ high RPM.

Large oval port= great street strip heads, and make good torque. These are good heads for trucks too

Small oval or "Peanut port heads"= Smog heads, low performance, High torque heads. Mainly used in trucks after the mid 70s

If your 1986 engine is still stock it should have peanut port heads.

As far as manifold goes. You have to use a manifold made for the heads.
You cant put a rectangle manifold on oval heads or visa versa.

Oval manifold will fit both large oval and peanut ports.

 

[aknight_sa]

There are 3 types of BBC heads.
Rectangular port= high performance heads= Good for high performance/ high RPM.

Large oval port= great street strip heads, and make good torque. These are good heads for trucks too

Small oval or "Peanut port heads"= Smog heads, low performance, High torque heads. Mainly used in trucks after the mid 70s

If your 1986 engine is still stock it should have peanut port heads.

As far as manifold goes. You have to use a manifold made for the heads.
You cant put a rectangle manifold on oval heads or visa versa.

Oval manifold will fit both large oval and peanut ports.

thanks for the info, now the heads and intake on summit are either showing oval port or rectangular ports..

thanks