Series 2 Help ! early type valve guides and seals probl

HI, I'm rebuilding my series 2A engine which has the early type valve guides i.e. with o-ring seals in the guide rather than the cap type. I purchased a set of o-rings (Bearmach) but they don't fit. They are too tight and tore when the valve is pushed in (very difficult).
Does anyone know where to source o-ring which fit ?
Are the "newer" type valve guides which have conventional external groove for the cap type seal compatible with the early type head. If I press out the old guides, will the new type fit ?
Any help much appreciated as I now don't have a way forward.

I don't know but @jamesmartin might?

Page 78 in my series 2a green book (operation A2 - 23) says the early and late guides can be changed but says there are complications with washers that fit under the guides and valve springs...

...seems like it is worth a read

Stretch said:

Page 78 in my series 2a green book (operation A2 - 23) says the early and late guides can be changed but says there are complications with washers that fit under the guides and valve springs...

...seems like it is worth a read

Click to expand...

Thanks Stretch, I'll look for a copy of the book. If you have the opportunity to post a snippet of the pages, I'd appreciate a preview. Thanks

Flossie said:

I don't know but @jamesmartin might?

Click to expand...

Thanks Flossie, I've sent a message with some details. Thanks for the link.