I am in the process of converting my 69 to floor shift auto. I think I have a problem though when i set the console base in its correct location the front of the console has a 2 inch gap between the bottom of the base and the floor while the rest lays flush. Is there a difference in auto and 4 speed bases or am I doing something wrong?

Everyone has to believe in something.... I believe I'll have another beer!:beers:

When I converted my 69 from a bench seat 4 speed to buckets and console 4 speed, I had to change the shifter hump. there is a difference between console and no console. I'm not sure about an automatic, as far as requiring a shifter hump, but should be pretty easy to find out. You could check an assembly maual or just check a parts suppliers catalog and see if they offer one.

there is no difference between manual and auto console bases 68-72 the top plate is what governs which trans it will fit. I am willing to bet your carpeting isn't in place when you're test fitting the console? If so the carpeting will take up the extra space between the base and floor.

As previously stated, there is a difference between manual and automatic shift humps. The auto tunnel has no "hump" to it. There are factory dimples in the sheet metal that dictate where the horseshoe shifter is to be located. The console base then attaches to the shifter mechanism. If you still have gaps between floor and console, I'm sure you can make adjustments with carpet, sound deadening, etc. But it should be pointed out that even when new from the factory, these consoles were not a perfect flush mount to the floor.
The short answer is... No, there is no difference (in the moloded plastic) between manual and automatic console bases for 68 to 72 Chevelles.
Hope this helps...
Patrick