Eric, when people first started building the 383 "stroker" they used a stock 400cid crank, with the large diameter journals, the 350 block had to be line bored to accept that crank, and they used a 350cid piston with small skirts, two things they learned .. the skirts of the pistons didn't hold up well to the increased wall speed, and the large journals of the crank didn't like continuous high rpm either, resulting in high oil temp and often spun bearings ... but technology has changed, the new cranks are a small journal, fit's right in the 350 block, with just a little block clearence being performed, and the hyperutectic pistons have teflon coated skirts to reduce friction against the cylinder wall. Like Steve said, the new style 383 "stroker" is a pretty tough motor, and the vortec head flow technology has awsome mid and high range power. I am building the 383, actually a 389cid, out of another 2000 model 1 ton truck motor, thick cylinder walls, 4 bolt main, and the vortec heads, just like my other motor, bored .060 and milling the heads some, stainless steel valves, "Z" springs and retainers, the new pistons are a bit higher compression, probably 10.1 compression ratio, but can still run the 91 octane pump gas.
Secondly ... I'm running a 1.47 gear ratio in the Gen II drive alright, ya got to spin it to win it, but the technology in props today, you can accomplish more performance with a good prop now, than we used to by changing out a set of gears to change the rpm some. I'm no prop expert, or mechanic either for that matter, but I'm adding picture of my prop here described as I understand it .. and like I said, I'm no expert, but this prop has been into the lab three times to get the most out of it, and it does really well, it pushes my boat into the low 70's at 5200 rpm. My friends at the prop shop made me a drag prop that I ran some, it was a 14 1/4 X 19 4 blade that would Shoot my boat out of the hole, but it turned the motor 6200 rpm, it only run a speed of 62 mph, but that was in 1000 feet in 13 seconds from a dead stop, but it was a Blast out of the hole.
One big issue proping out my boat was the modifications I made in the transom, I moved the transom box back 5 inches, raised the "X" dimention almost 3 inches, and changed the rake of the transom to 8 degree's, then added the nose cone, and it Finally came up to speed with the right prop. I don't know if I will get much more speed with the new motor, but my goal for this new motor is to get the boat up on plane faster with a load of gas, 52 gallons, and 4 or 5 people on board ... thats where it's sluggish now, and I want it to run flatter at speed flat, not run with the nose so high, when it leaves the water now, it lands stern first, I want it to land flat, but the only way I get the speed out of it now is to trim it up that much. We'll see?