Mechanic reports he inadvertently installed two B737-300 nose tires on a B737-700 aircraft; because he was in too much of a hurry to complete the nose tire change and did not verify the tire parts tags. A paperwork audit caught the discrepancy.

Narrative

I was assigned to aircraft; along with another Mechanic; for an MV2 inspection. The aircraft also had an alert for checking the rig on the L1 door because of pressurization problems. On initial walkaround; the #3 main and both nose tires were worn. I went to find a tire cart for -700 aircraft. The carts were being used. I went to another aircraft and found the -700 tire cart. When the mechanics were through with it; I took it directly to my aircraft since it had new mains and nose tires; but I inadvertently grabbed 2 nose tires off the cart that were for a -300 aircraft. I got complacent since it was a -700 tire cart and did not inspect the tires and tags properly as I normally would. The aircraft came in late (after XA00); so I also got in too much of a hurry changing the tires so I could start the other jobs on the aircraft. This also contributed to not inspecting the tags and tires properly. Looking back; I should have inspected any tire and tag completely that I install on the aircraft. I should also check MPD for effectivity. I can assure this problem will never happen with myself or the mechanic I am working with again.