Planning to build my A15 with an h89 head (question: should I get the H89's cam as well?)
Cams are cut based on engine size more than head designation. For the most part all the of the A14/A15 cams are identical.
And turbos don't care much for big cams.
dual DCOE 40's (which I have), and a Mercedes twin turbo (which I also have
One moderately sized turbo and one carb would be better. Blow-through or draw through? If draw through, one big SU or one DCOE would be ideal.
Proper headwork will be a lot more important that head selection or cam selection. You will need HUGE ports to flow that much air/fuel.
I also have to track down a h190, or do you guys know how well a ford 8.8 rear end from a mustang would fit under the car?
You will need flared fenders and high positive offset wheels. That's a very wide axle for this car.
Ideally, get one from an Explorer. That gets you disc brakes and an LSD, then have it narrowed it a bit to fit.
My goal is to run in the solid 13's in the 1/4
I would adjust your goals and shoot for mid-to-low 14s.
Making that much power from an A-series will be extremely difficult, and you will be breaking transmissions on a very regular basis.
Also considering different year pistons? I've heard the pistons for the A76 head have a shallower dish than for the economy head.
You don't want shallower dish for a turbo. To make the kind of power you're asking for, you'll need a fairly low compression, around 8:1 max.
The old man disclaimer: To make this kind of power with carbs and an A-series will be very difficult, bordering on impossible. If you're intent on using an A-series, be thinking about fuel injection, not carbs.
The second old man disclaimer: You're about to spend several thousands of dollars and possibly hundreds of hours to basically make less power than a mild SR20DET would.
And as I say a lot, "because you have it" is the worst possible reason to do anything.