shorty headers

[datzenmike]

They will all bolt on to each other but...

 

'78-'80 exhaust ports are round... all other years are square. A square manifold will work on a round port head (barely) better than the other way around.

 

All L20B manifolde are 4 into 1 with a single large round connection to the down pipe. All earlier ones are 4 into 2, with 2 smaller outlets into a two pipe down pipe.

 

All '75-'77 L20B exhaust manifolds are also bolted together with the intake manifold.

 

Does that help?

[Dawa]

^ just now saw this. it definitely helped ME. thanks for the info Mike.

the reason i was asking is if i buy a bare l20 block im wondering if i can use the intake/exhaust manifolds from my l16.

[banzai510(hainz)]

Early L20 had square exhause port heads(U67)

Later had round port heads

 

but if you use your squreport head yes the L16 stuff is perfect however the L20 will raise the exhaust up about 3/5 inc so calculated on that if hitting the floor of the truck or exhaust hitting trans x memeber

[Dawa]

^ ah damn. well thanks for that bit of info :)

[Dawa]

Hainz,

the l20 im buying has the square ports and im not going to swap the heads.

will the l16 exhaust manifold on the l20 (installed in a 620) have the clearance issue?

 

i apologize, i get confused very easily...

[banzai510(hainz)]

The exhaust manifold is not really the proplem. Its the Y pipe that fits it. As you have a truck youll nned the correct down pipe for that manifold tso it bends correctly and clears the bar.

Thus when the motor is taller it will move up also about 3/4 inch.

 

or get a new eaxhaust flange from Mklots and have a new Y pipe made. to clerwar this.

 

Or maybe if you have the ealry 620 you can shorten or make your Y pipe work if still good. Trial and error fit

 

best to ask a truck guy like Datfoug,Datsunaholic, Datzenmike ect.....