240z l28 Header Question

[Sanchez]

So about 6 months ago I was out of town and got a call from a friend telling me that I was getting fine notices for not registering my 240z which I had been working on (It is an early 1973 240z currently completely stock).  I told my friend to take it down to the muffler shop and have them throw on an exhaust just to get it passing inspection; well my friend knew nothing about cars and It showed when he was talking to the muffler shop because they overcharged him/me and put on one of the cheapest most restrictive exhausts you could imagine (1 3/4 in pipe, cheap restrictive muffler, non mandrel bent pipe, and they slapped it on to the rusty manifold).  I have been driving it since because I need it as a daily driver but now is the time to change it because I can tell that my engine hates it.

 

This is were my dilemma sets in.  I want to put an l28 into my car because the l24 is starting to give out on me and I am tired of putting in lead substitute everytime I refill costing and extra 10 dollars.  I also want my 240z to be running until I have rebuilt the l28 and it is time to drop it in, but with the exhaust It is becoming more difficult to drive.  I would like to put a header on the l24 and new 2 1/4 pipe all the way through the car.  However I am building on a budget and would like to reuse the exhaust once I drop the l28 in.  I have heard that the E88 (my current head) and the P90 (my soon to be l28 head with flat-top pistons) have the same square exhaust ports. 

 

Will a header built to fit an E88 fit on to a P90 head, and will the rest of the l24 exhaust fit under the car after the engine swap?

 

Thank you, I hope this all made sense

[BluDestiny]

I would go 2.5" piping. Yes the P90 head has square ports like an e88 so it will fit. I was acuatally using a square port header on my f54/P90 L28. 

[Sanchez]

Thanks for the speedy response. So one more question, should I purchase a P90 header from MSA and use that on my E88 for now or go for the E88 header and use that on my P90 when it comes time?

[NewZed]

The "P90" header would be shaped for the ZX body.  Look at the pictures on the MSA site.

 

The 70-76 header should have square ports.  Put N42 in the cylinder head ID box.  Or call them.

Edited March 21, 2013 by NewZed

[Sanchez]

Okay so I cannot get by on using just one header. I should get the N42 header?

[dat280z]

I would just buy the P90 square port header since that's what you are trying to run in the future.

 

-Antonio

[BluDestiny]

The "p90" header has egr and an o2 port. Which he doesn't have. Im running a non egr, no 02 poet header with a p90 head. I had an o2 bung welded on in the collector. So no dont buy a "p90" header, get a e88 header which doesn't have the ports that you won't use.

[dat280z]

^ I learn something new everyday

[Sanchez]

I talked to the manager of MSA today and he assured me that the 70-76 Header they sell will fit all Datsun z heads with square ports. Thanks for the help, hopefully this and some new gaskets will help solve my low vacuum issue.