L67 LPG options?

[storm]

Ok here's a curly one for you all. I'm starting to build an L67 (supercharged 3.8 litre V6) and am thinking about my LPG options.

In the long term the engine will get LPG injection (hopefully liquid but even vapour is better than nothing) but in the short term I will stick with a mixer system of some sort until my bank balance is healthy enough to go for LPG Injection. It may even be able to run dual flex fuel in a future incarnation.

After sitting down and working out airflow requirements of an L67 running 1 bar of boost (14.7 psi or thereabouts) I have calculated that at 6000 rpm the engine will need 802 cfm. That is assuming 100% VE naturally aspirated so 200% VE under 1 bar of boost. I know this is not the case but with boost you are better off over compensating so you do not cause a restriction within the supercharger.

So my thoughts are, 2 GRA throttle bodies or 2 IMPCO 425 mixers.

Neither option is easy with draw through but blow through is not possible on a standard configuration L67. So my initial, and maybe only, question is: are there adapters for a 425 (or even an OGH x-450) so it can be fitted within a straight through (no right angles) intake tract, similar to an IMPCO 225? The engine PCM will eventually use either an LS style MAF sensor or be tuned to suit a 1 BAR MAP sensor.

[C3H8]

If I understand your question correctly the Gann/impco adaptor for dual 425's vertical mount is AA3-80. Several are available on Ebay.

[storm]

I was thinking along the line of a horizontal mount that slips into pre-existing intake piping. Like the 225 in the attached picture.