If you're not blowing head gaskets, I wouldn't bother changing head bolts. The Kevlar pushrod guides work well with stock unhardened pushrods but will wear in a few years. They are cheap to replace, though. In the meantime, if you find a set of hardened Boss pushrods, they are slightly longer and usually help the rocker geometry when going to an adjustable valvetrain.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.