345kw of V8 Windsor Power
Join Date: Jul 2001
Is it the 200kw or 220kw engine? Both have the GT40P heads, but the 220 has larger valves and some minor porting. If it is the 200kw, I would look at some larger valves and a street/strip port and polish with the main attention to the bowl area and exhaust port. After that they should flow around 220i/170e cfm. If you have the 220kw, you already have the valves so you just need the port and polish.
If you have the 200kw wngine, it may be cheaper to go and find some 220kw heads and sell yours. You should get $800-$1k for yours, and the 220kw ones are about $1200-1400 from memory.