Lol. Everyone on this forum will say they suck, but it will work just fine. Most 1.0 pcms are calibrated for a 3.4 pulley, so you may run a little rich with just a downpipe.
You'd be surprised how many people are happy with just some fan settings changed, torque management changes and lowering PE some. That is basically what the dhp pcm amounts to. Also people try to run a 1.0 pcm with a cam or another mod that will throw off the tune, the car runs bad or chips a piston and they blame it on the pcm having no idea what that pcm is actually doing.