Here's were there is no comparison:
Cost to build a 69 Camaro (as example) to compete at the level of a new factory Camaro.
The new one gets no thumbs up or horns from truckers on the freeway - garners no "wows" from complete strangers and never causes a impromptu car show while getting a tank of gas.
At OUSCI 2009 there was a couple brand new modified Mustangs and a few brand new highly modified Camaros. Some were not entered other than for exhibition so not all times are posted.
The link here is to the RESULTS of the 2009 OUSCI. This is a competition that includes AutoX - road track - 0-60-0
Check the results out yourself. Note the times and distances of the 2010 Camaro versus some of the PT cars you ask about.
http://www.optimainvitational.com/media/results.pdf