I too in the beginning used a PTC converter. I will say this, I have two others by them and they work flawlessly. With my P7 combo, nothing seemed to work for it and was told there was nothing else they could do. I contacted another converter manufacturer and ended up with the same result after several test sessions. I then contacted A1 who is accustomed to dealing with high RPM comp style combos. Installed their converter (7") and picked up 3 tenths in the 1/4. Since that time, 60'...1.06, 1/8th...4.68, 1/4...7.41 @3600'. BUT like I said PTC does really good work and has a quality product which is obvious from the thousands of satisfied customers (me included). It just was not the best choice for a 10,000+ RPM 358" engine. The P7 is an animal all in its own and likes components most engines of the same make up don't. One thing we did find which was uncharacteristic for a short stroke, small cubic inch engine is it reacted better with lower stall (6-6500) than its similar (SB2)bore stroke combos liked (8000). Go figure? Like I said, Kenny @ PTC is a great guy with a large amount of experience and is as good as anyone out there IMO. FWIW, this P7 combo and converter is for sale on RJ Wanted to step up a class with what we now call a P607.... Hemi. Hope all my rambling of experiences may have helped.