I just happened to own one of those back then and comparing to a bone stock gn no way in hell it even comes close to the GN...they were nice gas savers but thats was about it even with full ford motorsport gear ....
The Turbo t I had for years ran 13.8 bone stock on a 48 degree day here at Englishtown. Even the original rubber was used. 13.8-14.5 or so was the norm depending on driver (60 ft) and temperature. GN was the fastest....it wasn't close.
i had an 84 gunmetal grey SVO in 87 and i got mopped by GNs from a start but on a roll i could just about keep up. but going around corners was a whole different story, it handled really good.