Summit racing has 2 pistons 2.904"
http://www.summitracing.com/parts/ue...75mm/overview/
They also have 2 that are 2.894" which is just under 2.9".
http://www.summitracing.com/parts/ue...-5mm/overview/
One is out of a 1987 Toyota L4 4-cylinder 1.5 liter
Not hard to find stuff, ya just gotta look..
Good luck