One problem you may have a problem with is a design flaw with the b-motor turbo. The all the stock 78-80's had a problem stock where they get the exhaust valves really really hot and at high RPM the valves will stretch or the head will crack. Also they had a big problem with detination and eating pistons at even 7.8:1 (i think thats it) and like 8psi of boost. But then again if you have that knock sensor you could use that to control ignition timing, are you going to run EZK? Marty will know more than I do since he worked on them when they were new hopefully he'll chime in.
And by the way get out of my head. We just got a 77' Pre-production Turbo thats hashed and we thinking of doing this to a 76 99.