Datsun Roadster Forum-311s.org

Does anybody know if all r16 cylinder heads are interchangable?I think I read some where that some are metric. Also are they all aluminum. My engine is a 1968
Thanks
Larry

i not sure about 68spl but i swapped an early r16 (sae) with 67.5 r16 head (metric) without a problem... i think the difference between metric and sae heads are the nuts and bolts on the valve train and the valve spring retainer/valve seals... also on the 68 and later metric heads has the air injection ports.

take care
ken

Datjunky is right-on. The early heads were cast iron SAE(my favorite) usually on the three main motors. The later metric heads with the 5 main motors engine #s 400001 and above were aluminum. I believe the 67.5's had the aluminum heads without the smog ports and then 68 and above all had smog ports. They are all interchangable with no obvious problems. I like running the cast iron heads on a stroker as they are more durable and less likely to warp than an aluminum head. To each their own though.

Steve

Not sure when the change took place but I've come accross a couple of three main 1600's with the aluminum head. Both '67s I believe. '66 may be the only year with a cast iron head.

Smog ports showed up in 69.
You can bolt an SAE head without any changes.
The tappet noise may change a little after the install because the original rockers,pushrod and tappet combination were broken in together and match up.
A replacement rocker assy sometimes depresses the pushrods at a slightly different angle and can create alot or little more tappet noise.
You can remove your original rocker shaft and rockers and put them in the new heads rocker towers to avoid this.
Ensure you mark the rocker shaft to enable you clock it back into its original wear position. The rockers will also have to be in the original positions.

Ray B.

Smog ports were added to US heads in '68. Some countries never got them so had non-smog heads all the way through production. Early '67 had 3-main engines with aluminum non-smog heads. '67.5 had 5-main engines with aluminum non-smog heads. All R16 heads are interchangeable, and I believe G15 heads will interchange as well although combustion chamber might be slightly different size. I've seen lots of mix & match, like cast iron heads on high windshield engines, late engine blocks in early cars with non-smog heads, etc., etc...