Save yourself a lot of work and experimenting.
Here's the place I was thinking of
http://www.badlanzhpe.com/page6.html
It's been a few years but he told me he would set me up with a 4" valve, two weld on flanges w/ gaskets for it, all the wire including a nice looking shifter mounted switch for around $175. He would provide clamp on flanges for the same price.The set up without the flanges is still $150 so I guess the price hasn't changed much. Very nice looking products.
The gasser racer guys use these valves to bypass the muffler with a Y in the pipe.
Please remember if you have the butterfly closed anything over an idle will cause engine damage even with a hole drilled in the butterfly.
That's the reason all the e-brake manufacturers have a switch on the throttle linkage.
Sort of the same reasoning why you use your right foot for the throttle and brake, so you don't do both at the same time.
__________________
Bill
'95 2500 4wd auto
'95 3500 5 speed heavy hauler
Not stock
Last edited by illflem : 01-08-2009 at 04:45 PM.