Yes, all late heads are interchangeable. See A-series Cylinder Heads for identification and more information.

But between the engines, are the heads and such interchangeable?

What can I look for when trying to identify an A series engine?

Yes, 120Y is A12, 130Y is A13, etc.

The block are all different. There are at least two A14 blocks. A15 blocks are unique. At least three A12 blocks. A12A block is also different.

Okay, understood.

Few final questions;

1. Are the A-series blocks identical other then casting numbers and bore size?

2. Wikipedia says that the Sunny was badged 120Y, 130Y, 140Y, or 150Y. Is that based on engine? 120Y being A12 and 150Y being A15?

I wouldn't say that. Instead: using a 1977 non-5-speed head on a 1981 engine is a power upgrade. Regardless of which A-series engine we are talking about.

The 1977 standard head is 80 HP. The 1981 head is somewhere aound 65 HP. Which is about the same as a 1977 5-speed head.

So using an A14 head on my A15 would actually be an upgrade? That sounds like good news, especially since my goal is to produce good power without forced induction.

Not correct.
A14s & A15s generally used the same head for the same year.

For example:
* 1981 & 1982 USA cars used the same head
* 1977 used a different head than 1981

The 1977 standard is a high RPM head (except 5-speed 1977 which got low RPM head).

The standard B210 head is an upgrade in peak HP for any 1981-1982 engine. I'm not sure but I think the 1981 head (medium oval ports) is better than the 1977 5-speed head (round ports).

I damaged my head and I'm looking for a replacement. Pull-A-Part has a 77 B210 in the yard. Assuming it's an A14. I read that they used the same head as the A15 in the '81 210. Is that correct?

I don't want to go all the way across town for a head that's going to be a downgrade on my car.




Thanks,
Matt