This may have been posted before but i found it interesting and have posted this link for those interested..

http://forums.corral.net/forums/svt-doh ... onals.html

Yes and this is of course about Modular pulleys not small block ones.

Yes i now its about the 5.4 litre quad cams as in the Ba - BF Falcons and FPV still found it interesting .just wondering how safe the underdrives really are has anyone had any oil pump gear failures was thinking of fitting some to my BF GT only reving to 6500pm so it should be ok but was still abit concerned.. Sorry didnt mean to post onto this thread meant to start a new one sorry again new to the forums still getting used to it all..?

You outta know you posted it...it was for other people that I mentioned it was for modulars.
I've got a set of Powerbond underdrives on mine...they work good. I've had no failures with them.
The damper assembly on them is large in diameter hence no problemo.
An ATI or Innovators West would be better still though. You won't get as much underdrive of the accessories with them but it's a small price to pay.