RedBanner's To Blame For This. . . :)

[METSystem]

Autozone, costless, or oreillys should be able.to get you a felpro v.c. gasket. Only way to go man.

It was a Felpro from O'Reilly's . . . I'll have to check it out again and see if that barely audible snap I heard and felt meant anything. . . Oh, the joy in Mudville. . .

[METSystem]

I was just reading on the internet that the L20B in 1977 was a midway cut off year between having the square exhaust port (75 to mid-77) and the round exhaust port (mid-77 to 80). Any way I can tell without tearing mine down before it's absolutely necessary?

[Laecaon]

What is stamped on the passenger side of your head?

W58 would be round. U67 Square. Those are the most common.

[flatcat19]

Common was to have a W58/round port on that year.
Could have been swapped out though.

Never know anymore. Not with Datsuns.
Considering the L16, L18, and L20B all will fit into the same hole.

[METSystem]

What is stamped on the passenger side of your head?

W58 would be round. U67 Square. Those are the most common.

I seem to have a U67 on the side of my Datsun's head.

Anyone know the benefits or drawbacks to either one?

[Eagle_Adam]

U67 is the large valve head if i remember right, most of them are open chambered.

I haven't read the thread but what are you trying to get out of the motor

[Laecaon]

U67 is a great head. Largest valves (besides infamous 219), and largest intake ports, but all are open chamber.

square port you have then.

[METSystem]

U67 is the large valve head if i remember right, most of them are open chambered.

I haven't read the thread but what are you trying to get out of the motor

Right now, I'm just trying to get it, and the whole truck back to stock from the years of monkey business under the hood along with the electrical oddities the PO made the truck the subject to with his Frankensteinian experiments. With the head questions, I'm just wanting to know what I have, that way when I have to go to a parts counter, instead of sticking my finger in my nose, swirling it around and pronouncing, "Duhhhhh" correctly, I can do it the right way the first time. . . .

The future of the truck is that it will not remain stock on the exterior, but I want the drivetrain normal so my wife can use it as a DD instead of our 15 mpg Jeep Cherokee. I'm looking to make it a good looking gas saver! If the paint doesn't clean up well, I'll repaint it in close to the original color, then I want to dip the front and raise the rear. Put some nice wheels and tires similar to my first 78 620 (the Red one in my avatar). After that, then the sound system goes in (it still has the right side on/off AM radio that probably came with the truck in 1977), then the interior is changed and that may mean a whole new or custom dash. The current dash is a wreck!

But, all that is on hold until I can solve this blasted oil leak. I'm starting to worry about a rear main seal. And if it's that, then the engine's coming out and a reman is going in .

[Eagle_Adam]

a rear main is easy on these motors, drop the trans and you can borrow my installer tool if you want.