Toivonen Estoril Lap

Does anyone have a reliable source that suggests that Henri lapped the Estoril track at a pace that it would give him 6th place in a starting grid?

I mean, those group b monsters were heavier, had less horsepower and didn't have as much downforce (but yes, it had 4wd), so I find it very unlikely that performance and I'd really like to have confirmation of this.

Ive heard that in the past, I would like to know if its true as well.

This has been discussed on Atlas F1 Nostalgia Forum (http://forums.atlasf1.com/showthread.php?s=&threadid=72509&highlight=toivonen+estoril) the consensus seems to be that it it highly unlikely.
Look particularly at the comparison from the Goodwood Festival of Speed.
There is also areference to what may be the original claim on a rallying website.