We tried the manual with an RPM built T56. They failed miserably which led me to the TH400 from a different vendor I have now. Nothing wrong with the transmission at all. It is a convertor issue. You can compute the slip at nearly 40% @ 6300. MPH doesn't rise between 6300 and 6900. I have a local guy who has been very successful and has agreed to help us get the stall right. Otherwise I am looking hard at Twist and a couple of others.

So we've concluded that the 245 mm Convertor just cannot pump enough fluid to work right with the weight and power we are running. We are building a 265 mm Convertor right now. The guy that is building the convertor is going to try a design he has developed himself that will involve a custom built steel stator with different angles than are normally found. I guess we will see soon.

Got a new converter in from a local shop, guy nailed it on the first try. Back to they dyno to dial in the toys and busted the FAST 102 at 27lbs boost. Sending it back for them to look at it.

This car is insane and you blew apart a FAST intake. Crazy!

Well we split three runners, didn't really blow it apart. FAST is a great organization to deal with. I would like to keep the FAST with a 102mm TB as opposed to a 78 mm with the LS1 TB.

very nice!!!!

So was this an isolated incident, or will this happen again with a new unit?
I've always wandered what kind of boost pressure the FAST intakes would handle. Do you anticipate having to go with an aluminum intake?
Is FAST going to replace this under warranty?

They advertise to 60 lbs I think. The guys at fast said that it should not have had a problem at 27 lbs. I am thinking I may end up with an aluminum intake just so I can maintain the 102mm TB. The LS6 we have on there is pretty robust but only has a 78 mm TB. On the warranty they are going to look at it and I have no reason to believe they won't replace the runners.

We are enroute to an LSX block. Going to up the Ci to 427, using same crankshaft and rods from the 408.

Fwiw I don't think it would be a problem for you to run that. I've ran a 408 with twin 66's to 1150rwhp with an LS6 intake and 78mm throttle body and that power was right in line with other combinations we did with larger throttle bodies and intake manifolds.

Not saying the fast intake and bigger throttle body wouldn't help at -all-, just that I don't think it would be a huge difference.