I would think that even a internet novice would be able to gleen that info on the information highway. By simply typing in wenzler manifolds I was able to find it.....took all of about 5 seconds:
http://www.wenzlerengineering.com/PONTIAC.HTM
If the O/P was savvy enough to send an e-mail.....he can easily find the # to call. I would assume it is much cheaper for him to e-mail than to call (since he is from the U.K.)