In need of some help.

[71enthusiast]

Well the title states it all. Here is what is going on:
Recently I upgraded my transmission to a th350. Ever since then I've had to pour many of quarts into the tranny whenever I wanted to go somewhere. It was clear that there was a leak but there never was a puddle when I parked it.
So after 4 or 5 gallons of ATF I began to experience some light tail pipe smoke and loss of power. Presumed it was the carburetor at fault but many of tunings suggested otherwise.
It got to the point where I was so annoyed with my motors performance that I had to get to the bottom of this. Well I found cylinder 1 to be misfiring, replaced plug, ran great for maybe 30 miles. So I said "screw it I can make it back home. " needless to say I didn't make it home. Nope about 6 miles from my destination I lost every gear.
Phoned a friend, filled my Trans fired her up an lost all visibility due to a curtain of smoke coming from the exhaust. Well it drove fine so I brought her back and parked it.

I went out to the garage the other day and found a good size puddle under the passenger side engine bay. I checked the oil level and it read halfway up the dipstick. (not halfway as in between the marks but between either end of the stick itself)

The oil looked clean no milkyness whatsoever but the radiator was 75% full even after filling it before the trip. It as well is as clean as can be.

I'm curious if there is a head gasket leak since cylinders 4 and 6 look pretty nasty but if that was the case wouldn't my oil be milky?

And where is all my ATF going!?
Please someone shed some light for me so I can fix this

Some specs:
Gm 350
Edelbrock carb
Rockers and push rods passed visual inspection
Th350 Trans cooled through new radiator