I've got a blown 84 vette with crossfire... so to speak..
Hey, I've got a Crossfire with twin turbos on it. It's really fast. Waste of tires if you ask me. I brought the PSI down to 6 for less boost. Once things spooled up, rubber got out of hand...
First thing you should do to your crossfire engine is bolt on an X-Ram intake manifold. You can turbo it all you want and not get any extra power out of it. The X-Ram lets the motor breath in way better.
You might also want to change the inhood induction. Limiting to say the least but I made some make shift carbonfiber vents going to the front on an aftermarket hood and it worked wonders.
After you X-ram, depending on what other modifications you have to your engine, you won't even want to Turbo, trust me.
1/4 Mile in 11.2 on pump gas.