exhaust options for 1969 428 super cobra jet

1969 428 super cobra jet mustang manual that is very mint 100% origional condition but is way too quiet. The current exhaust configuration is twin 2.25" pipes from ramshorn manifolds through straight pipe mufflers and on to the rear of the car. There is no local requirement for cats but there is a balance tube between the two pipes. BUT it is so quiet!

What suggestions for better performance and hearing the motor growl! Note Chopping and cutting panels or chassis is not an option

If it is a mint original I personally would return the whole exhaust back to factory spec or at worst foactory optioned type.

A care that rare in NZ should be kept original I reckon.... (my 0.02)
[addsig]

Go with dual 2.5 pipes use the xpipe or cross tube, that is good for low end grunt, then use 2 chamber Flowmasters do the N20 Mike trick of welding header flanges there then buy the flowmaster"mandrel bent"over the axel pipes so you can run them dumping in front of the axel or out the back when the hearing starts to go!
[addsig]

Is there a formula for exhaust size and length? Or has anyone a similar combo that performs well and sounds good?

The formula is this:stuff the largest exhaust pipe you can fit under the car, most Mustangs struggle with 3 inch and you can't get 3inch over the rear axel so use 2.5 inch and really good flowing muffs.

Theres a set of exhaust tips on E-BAY for a measly $6500 bucks[img]/phpBB/images/smiles/icon_eek.gif[/img][img]/phpBB/images/smiles/icon_eek.gif[/img][img]/phpBB/images/smiles/icon_rolleyes.gif[/img]Take a look in the garage for the link.