Do I need to cut valve seats if I put new guides?

[MatthewBrum]

I would like to put new guides in my 80 SC heads, if the valves and seats look good do I still have to do anything to them.

thanks-Matt

[Henry Schmidt]

It is nearly impossible for a new guide to install in exactly the same place as the old one.
The relationship between the valve and the seat is determined by the guide.
If you replace the guide you must recut the valve seats, no exceptions.

[MatthewBrum]

Henry thanks for your reply, I will get the seats cut

[hcoles]

I hear that the best cutting of seats is done with a "Serdi" type cutting machine... you might want to have a place that has one of those machines do the job.