3000 is a bilge pump
. 29090 is the model # for a Jabsco manual toilet...-3000 or -5000 only refers to the size of the bowl.
Check out the Raritan
SeaEra...Practical Sailor rated it "best bargain buy" in a comparison of macerating electric toilets a few years ago. Raritan SeaEra Promo Sheet
The the pump motor
assembly can be oriented to go out the back or to either side of the bowl. That'll become clearer to you when you see the drawings on page 5 in the owners manual Raritan SeaEra owners manual
. You'll also find dimensions for it in the owners manual.
You can get it as a "conversion" --everything but the bowl, seat and lid, which means you can re-use your Jabsco bowl seat & lid (yes, the bowl WILL fit!) AND save some $$.
This retailer has it for the best price
I can find Boatersland - Raritan Sea Era Conversion Kit
I'll be glad answer any questions about it...