Rectifier For Cary SLP 05

I am currently using a Mullard GZ34 and have been for a while now. on a Cary SLP 05 preamp.

i am shopping for some back up replacements.
Will a Brimar 5R4GY be a drop in replacement and if so, what sort of sound does it have compared to the Mullard GZ34?
Is Dan Wemmer still at Cary?
No reply as yet and it is way after the weekend.
I use one of those gigantic 274b rectifiers because it's simply so cool looking, and it seems to work well...the "preferred" version. Might not fit in some amps.
Just an update so other folk will know for the future. Cary says it is electrically the same but will not fit because of the size.
Also, they don't recommend a directly heated rectifier 5R4 or 5U4 on the SLP-05. " Use indirectly heated tubes like the 5AR4, 5V4/GZ34, CV1377, GZ32, GZ33, CV729."
In any case, the reply came too late as the seller couldn't wait and sold the Brimar. Not that it mattered in the end.