I have an 8" Ultimate that was built for my 408, it never 60' (1.38) within a .1 of the 9.5" converter it replaced. Most of the time it was off .13-.15. When i pulled the 408 down to freshen I discovered my block was flexing so I decided to go a different direction. I found a Indy headed R1 engine that was apart and built a 434 using the block, heads and intake. I called Lenny after dynoing the engine and we talked about the converter. He thought it would be close and wanted me to try it, so I did. It was slipping 18% at the 1/8 and the 60' was in the 1.55 range. On the phone again and Lenny says send it back. He tightened it up 500 rpms, it now runs 1.44 60' and picked some mph.

The thing is it should be low-mid 1.30's IMO with the extra power the new engine added.

Nothing personal to Lenny as I think he's a good guy, but I have about $1600 in this converter and it doesn't work. I've talked to Kenny at PTC and I'm pretty sure that's where it's going to see if he can fix it.