How would I be able to tell what turbo I have on my 85 volvo 740? Which one is better to have for more power and reliability? Whatever turbo is on there It seems to spool up pretty fast with alot of power at low rpm's but at around 3000 rpm's (just a wild guess, haven't really paid attention to exact number) it seems to have no power. And when you get to about 4000 rpms the tach moves so slow. The boost guage shows high boost but must be beyond where the turbo can make power. I have adjusted my waste gate so that the boost goes just to the red line on stock boost guage (gonna give more boost after I fix oil leak on oil return line), I took factory air box out and put a cone filter in its place, and I added an aftermarket bov to run along with stock relief valve. So im just trying to figure out some easy cheap ways to get more top end. anny suggestions?