Thanks for the replies everyone after doing some further research and alot of thinking
I have found out the diff is a old banjo 2.78 which could explain my memories of lack of boogie LoL

So with that I will look around for a better diff maybe a 3.08 (want to be good a high speed but still have some off line ability - any advice here ?)
I will stick with 253 check out how much gas system is to get recert. and then get it roadworthy for rego .
Have abit of time cruisen and seeing how the new diff affects grunt then see if it is warranted to get 5ltr EFI

Any recommendations on 253 while I am working on it to get better performance - without pulling it to bits internally ?

Also does any1 know if you need pollution attached if equipped with LPG for Roadworthy?
My manifold etc doesnt look to have bits to set it up mmmm ??

Cheers again every1 for replies it has helped me be clearer about direction to take

Hairy