Due to their rapid victories, no one ever realized just how weak the Nazis were. Hitler like Bush tried to fight his wars on the cheap with advanced technology. Only problem was that wouldn't work against the vast spaces of Russia.
So how do you solve the problem??? Simple, Albert Speer is made Reich Minister of Production in 1934 instead of 1943. The effect is cumulative. Speer streamlines the beaucracy, merges several design teams, and actually upguns the Panzers at Hitler's request instead of vacilating. This speeds up Hitler's rearmament.
Hitler has more trucks which will help greatly in Russia where there are not a whole lot of conviently located civilian gas stations as in France.
Heinkel gets the fighter contracts instead of Messerschmitt, this give the Luffwaffe a far more manueverable, faster, and longer ranged fighter in the HE-112. This will cut down German Bomber Losses signifigantly. Will it make Sea Lion possible? Perhaps, if it were an Airborne Operation with a couple of hundred transport planes to support an airhead and capture a few Airfields till an armoured division can vault the channel under heavy Luffwaffe support. Even thats not a guarentee. The English Channel is, "Rough on invaders."
Panzerfausts enter the scene earlier. This improves the German Infantryman's firepower considerablely, "If a panzerfaust can wreck a panzer, it will wreck the machine gun nest in that house just as well."
Radar is fitted to the Kriegsmarine's Ships. That makes German pocket battleships far more accurate and deadly in their gunfire. This will have serious repurcussions at Norway. Especially if the Graf Zeppelin is completed.
Synthetic Oil and Rubber production go way up and and that translates into a more efficient economy.
Last all this production boom means alot of obsolete Panzer 1s and 2s would be exported in 1938 as almost happened in our timeline. Most would probably end up in Persia or in China. The U.S. Marines would probably negotiate for the Panzer 3 as a way to get around the Army hogging all the armoured vehiciles. A few of those Tanks end up on Wake Island where they prove instrumental in defeating the second landing attempt by the Japanese.
Then comes 1939 all hell breaks loose. There is a lot of speculation I left open so you guys can have fun in thinking what ten more Tanks there or an extra truck load of fuel here can tip the balance. Let the speculation begin.