1396midget wrote:my eventual plan is to get rid of the middle box and fit straight through silencers on each of my twin pipes, but I won't be doing that till the existing bits rot out. RC40 straight through silencers designed for minis and good for up to 150 hp, one on each side. They have the advantage of being very cheap (27 quid ish). I've got one on the MG and it sounds great.
Too loud? Only one way to find out!

If you haven't already done so, have a listen to some YouTube clips of TVRs (V8) with similar set ups. Many have removed the main and pre-cats, and then made the silencer straight through. It might give you a rough idea of what it might sound like.
I appreciate that the headers etc are different, but there are differing schools of thought in the TVR world. Some love the sound, others think that it sounds a bit 'tractorish', particularly at tickover. Some have gone down that route and then reverted to standard spec (which isn't exactly quiet) as they have found that it drones a lot on long journeys. Others have opted for the 'decatted' sound but left the original silencer. Others have removed some, but not all, of the wadding in the silencer as a half-way measure.
It's all down to personal tatste and preferences. There are some who have found a loss of power (tested before/after on dynos) after going to straight through, but that might not be a concern.