Kitchen Devil : The topic was refering to running a T34..........Not a T38, and from your first post you made no mention of it running a T38. Hence I stated what I did.

With your T38, 450BHP on the engine you described is a very good figure. However, I'm only trying to help people from my own experiences over 16 years of Cosworth ownership and Engine Builds. One bit of advice though (It's down to you wether you want it or not).....But at that BHP Figure, keep an eye on your AFR's if you do any long high speed runs, as the greys are honestly on their very maximum cycles, and any degrading over time of the injectors will lead to your engine running weak, and melting pistons.

Only Offering Advice

By upgrading to Siemens Black injectors, you'd get even more power (Maybe), but you'd definately be running with a safety margin that would protect what appears to be a very good engine, putting out those figures.