I still need to find an engine for this kit, so if anyone has any info regarding after market jagdtiger engines in 1/35 scale i would appreciate it.
It depends on what you want to do with it David - how detailed you need it. The Tamiya German Tank Maintenance set is only good for an in situ placement as the block is moulded in one lump to the false floor section:
A look through the hatch and it will probably be detailed enough.
Otherwise, with the top deck removed or an engine being lowered in, etc, you are going to need more detail. If so, first up, I would put up a post here asking if anyone is not using an engine from one of the recent kits that come with an interior... you never know your luck someone might offer you one for the cost of postage or at least a cheap price.
Otherwise, CMK do a Maybach HL 230 P30 for the King Tiger - kit 3064.
Verlinden did one too.
There is this 3d Printed one:
their website pic:
There used to be another on Shapeways, but that seems to have disappeared from their site.