I haven't seen the specs on the AD Eng. kit. Honestly, I wasn't greatly impressed with what I saw for the price. I hope there's more to it than they showed last time I checked it out...
The determining factor is (of course) the length or height of the cab mounts. If memory serves me correctly, to get stock height, the cab mounts will need to be about 6". This is because the s-10 has a dip in it, where the original frame is a straight line. A 350/350 *should* clear it at that height, but I think its a bit close at the toeboard/floorboard seam. If you plan to use a floor shifter, I think that may be a tight fit unless you use something like the nostalgia shifter from Ididit.
This is primarily speculation, because I opted to drop the body a couple of inches for a lower center of gravity. I had to cut into the toeboard about 2-2.5 inches (toward the dash). The stock width for the transmission pan was maintained, so I just have to build a new transmission pan to fit the opening. When I parted the S-10, I cut the tunnel and kept it just in case part of it could be used.
Another note on these swaps, I haven't found the specs, but the s-10 bodies are incredibly heavier than the AD (I'd guess close to 200 pounds). The frame sat lower to the ground with the s-10 and 2.8l than with the ad body with a 5L olds and 350 tranny (same springs)...
