Originally Posted by: KBM my FJ75 has recently been upgraded from a red 253 that was out of my old HT wagon to a blue 308 out of a WB statesman that's been rebuilt and only upgrade is a cam to suit straight gas. the same gas research system on both motors. I wish I rebuilt the 253. on flat ground the 308's fine, and so was the 253, but when you hit the hill it's crap. the 253 out performed the 308 easily. My standard 307 wagon is much better than the 308 up the same hill, except for the sharp corner where the powerglide doesn't kick down and takes a bit of time to reach 90kms again but it's only got a two barrel. the hill is my way home every day and in 8kms rises about 600m.
My stock 253 HG would flog a stock blue 308 any day, I mate put a WB Statesman 308 in his WB 1 Tonne with a VP 5Speed behind it and 3.36 diff, extractors and 3 inch mandrel single exhaust and it did not go hard at all and then he put a Crow torque cam in it as he was a Builder towing a huge trailer, it still was a slug that would not eat a HG 253, but his 308 may of made more torque.
He thought it went well and I said it was a just a slug, my 308 would of killed it.
I had a Dyno tune on my 308 that had a small cam and L34 valves and that bastard made it loose a lot of power, he recon that I could not afford to drive it the way it was jetted
I had been driving it for 6 years and getting 22MPG on the highway with that jetting and after that prick it got 16.5mpg and the vacuum advance happened to not work after that clown messed with it and one hill I drive up I had to put my foot down going up it, when it never used to.
With that crap jetting it loss power so much so that it was unbelievable, so a carby jetted the correct way can make it perform a hell of lot better.
Now with this in mind HK1837 Says if I remember correctly that the carby jetting is no different in the pre emission 308's to the emission ones, but I have seen that the Ford V8 jetting is different as time goes on from the first ADR27A and the V8 F100 is different to the cars jetting, maybe the main jet is the same but the metering rod is a different part number and I am sure that the Holden V8 do change with ADR27A, but they will be lean I am sure and that means gutless to me, not to mention that to rich makes it gutless as well. but just the right getting makes the big difference.
I spend the time mucking about jetting my dirt bikes just right and it sure is worth it as the factory settings are rubbish with every new bike I have had.