does anybody know if the military boxes with the parkbrake drum on rear of t/box are an overdrive box or a straight thro 1:1 ratio top gear??...is this basically the civvy box? are they the same? ive found a '99 4l80e (so the bloke says) ex military gbox for sale and might buy it and fit it to cure my leaking casing problem...are there any strength improvements to the g/box or the t/box? and do you think it will fit ? i can do away with the cables running to the rear axles and 'disconnect the linkage....? any info at all would be appreciated....