Battery Pack's REAL Dimensions

Hello all
I have a strange question:
I have bought a 4s 40C 5000Mah flightmax battery pack for my converted RC8t. The dimensions of the battery tray of the car (original associated e-conversion) seem to be smaller than the "declared" dimensions in the manufacturers site (I don know if I can post the link here, but the declared dimensions are 147x31x56). The battery tray in the e-conversions is shorter (only 140 mm), but the pack still fits (!)
Now, here is the question:
I thought of buying the Turnigy packs (4S, 40C, 5000Mah). But these packs' declared dimensions are 149X49X37. Does anyone know if these packs actually fit the e-conversion's tray ?

another thing : Does anyone have actual experience with both packs ? any conclusion ?
Thanks
Billyboy