Sorry but you are wrong Hib, I used to own a TTA , #5 to be exact.
They require different headers than the Buicks.
Here is a very informative post , look down a couple posts :
http://www.turbobuick.com/forums/thr...-ports.391515/
They didn't make a "specific head" , they used already commercially available heads off the "3800 traverse v6" engine already in production that actually outperformed stock lc2 Buick heads!
" It was fitted with cylinder heads from the existing traverse V-6 3800 Series I heads, PN: 25536702, which yielded superior combustion chamber design & exhaust flow of the GN/GNX design. It allowed room for the downpipe to fit, and also gave more clearance around the strut towers & A/C box on the firewall. " ---