And i'm all so going to go with jdmdatsun510 and what till i blow a head gasket or something then pull the head of and get a wade 25/65 cam because i read the form with cams and they said that crow cames should be left to v8's wich i agree with.

I only take my engine to 5500RPM. Stock max power output is around there anyway.

Cam shaft will change where your max power is produced. Sounds like your stock carby is pretty well stuffed.

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89' R31 Skyline Ti, 5 speed - Daily
89' R31 Skyline Executive - Slider/track whore
8' Stanza SSS - Rally Project

my 180b would sometimes "run-on" when I first bought it. I put it down to shitty fuel. Back in the 70's fuel had lead in it as we all know, which upped the octane rating and I think the rating of super was about 96 (same as premium). Unleaded today is 91 ron (I think) and if you don't put additives in such as flash lube you not only risk damaging your valve seats(unless they're hardened), but the engine may ping which is not good either. I run flashlube in my car with unleaded and add a little extra (not much extra) and it hasn't "run-on" in a year.

As for everyone mentioning the factory headers on L18s are good. My L18 is a 1976, and the header is the factory cast unit, and the pipes are not of tuned length. Is this still a better option than going for an aftermarket extractor 4>1 header?

all L series heads have brass valve seats for ULP from the factory - right from day dot.

along with A series.

the factory headers are good up to about 150hp at which point they become a restriction. to get the best out of your motor i'd say use good tuned length headers from about 120hp and up.

they're just a cheaper option and as we all know, Datsun were pretty switched on with all their standard product. they had to be - some classes required factory EVERYTHING bar carby and exhaust post headers.

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frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.