Hi,

I have an ef 5 litre on gas with 225 impco mixer. I have seen other cars running the 425 mixer and am thinking about putting one on my car. Anybody out there done it??
I am curious to know if it would go better (feels a bit strangled at the moment)?? I realise it is never going to compare to gas injection!!
The car is running a gas cam, gt40p heads and au intake.

Thanks in advance

Fitter

The 425 is the only size mixer i'd use on a 5L.
Its easy to swap any good Impco supplier will have all the adapters and brackets you'll need.
I would also recommend running the Model E or L Impco converter as they flow better and run more stable pressure output with a 425. And they can be modded to flow even more with heavier primary and secondary springs. There are also alot of secret mods that can be done to make these babies flow more than anyone can believe!!
If you have a LG B2 converter already I would suggest getting the HP spring kit for it. It boosts output to flow about 375Hp. Its a set of heavier (stronger) primary springs and brass buttons to protect the diaphram and a stronger secondary spring. This increases vapour pressure and flow and will make you car respond better on acceleration and more stable to tune.

I also mount the converter directly to the engine on 5L E series right next to the throttle body and mixer with an adapter fitting between the converter and mixer. This also increases throttle response as there is no long vapour hose for mixer signals to have to travel along to get to the converter on the other side of the engine bay. Also looks much neater.