Chevrolet 6 liter motor what does it equal?

I am assuming that you mean what does it equal in cubic inches?

Multiply liters by 61 to get approximate cubic inches.

Thus a 2.8 liter engine is 2.8x61= 170 ci (allow for some variation, but you can get close.

SO a 6 liter engine is 6*62 or about 370 cubic inches, give or take.