anyone know what the production month or casting numbers for early and late E88 heads.I have a 240 with production date of 5/72 with original engine on engine stand.I have a L26 engine with E88 head as well as 71 SU's.Any difference in the heads?Thanks for any and all help.

I don't have any answers for you but I'd love to know the answers to this as well. I think the E88 heads got bigger combustion chambers in 73' in an effort to lower the compression and reduce emissions. If that's true, I would think that an E88 from a 71 or 72 would be a better choice if you're looking for higher compression or betgter performance, although I'm not sure it would be enough to notice wihtout other mods. Here's a link to some info on various heads.

http://www.geocities.com/zgarage2001/z.html

the early '72 e88 heads, or the ones that came on the 240Z, have smaller exhaust valves as opposed to the '73 e88 head, which was on the 260Z, which has larger exhaust valves. Another difference is the quench chamber, the design of the 240Z e88 has a lip where the spark plug enters the cylinder, whereas on the 260Z, there is no lip.

I have used both years of e88 heads, and so far, I have not noticed any real performance difference.

Its confusing that same "E-88" head has at least 3 variations?

71-early 72? have chamber size and valves of E-31...with better flow then E31, or so I've heard from several sources.

72-73 240 E-88...larger chamber same valve size.

73-74 260 E-88...larger chamber, bigger exhaust valve....