so the conclusion is, if there is enough "meat" on an a12 manifold, then it can be ported to match the oval port. and the A15 head can be drilled and tapped centre port to suit. yeah?

If it drives straight, and doesn't chew out the tyres then I wouldn't worry about it. It always worth a second on those things too.

ps. hope it works out ok for you

On the intake manifold studs, do these accomidate both mounting systems of the A12 and the A15, or is that just the one I seen?

To overcome, and also remedy each end of the discussion, would it not make sense to have the gas flow from all four cylinders to be split evenly to each turbo. This would decrease pulsation. Then have each turbo feeding the same four cylinder intakes through a plenum design. The smaller turbos will spool quicker because there is less enertia and mass to overcome. All said and done, the twin turbos would look great and it has sparked a great Discusion.
Sorry phunkdoktaspok I was intending to say that in my belief the argument that L18 had, was slightly more weighted, though you both have a valid point. With all things there is a payoff. you have to way up the positives of each, and decide on what you want to compromise.
But as we know, the decision has been made, and as enthusiasts I think we can find way to make twin turbos work on an A15.

I was wondering what thread I put that in
I couldn't find it again, trying to locate an A15 electronic dizzy on ebay and submitting post at the same time does not work to well together with sleep deprivation
But on the point of carbies any thing will fit if you've got the time but the easiest way is to put an A15 one on with auto choke, works a treat

A bit off point but closely related, why run twin side draughts and have the fuel pulsing in, why not run one big carb and have a constant flow?
and to note, I agree with L18, the rules of logic apply.

on the point of twin turbos, I feel both turbos should be evenly fed by ALL cylinders, through a pre turbo header type arrangement. will it work hell I don't know but its another idea

Replace the condenser, or fit electronic distributor. .
check yout leads and plugs too.

If you swap the lower gear over, machine the adjuster face and adapt the original A15 steel adjuster plate to the E15 distributer. then yes it will fit.

I have found that some turbo CA engines run 500cc injectors. If that helps?

Recaro, S/H isuzu bighorn, toyota starlet, Nissan 200sx.