Super Mario Kart:ROM map

Item (in box) Tile/Palette Assignments

USA=0x1B320-1: (Mushroom)
USA=0x1B322-3: (Feather)
USA=0x1B324-5: (Star)
USA=0x1B326-7: (Banana)
USA=0x1B328-9: (Green Shell)
USA=0x1B32A-B: (Red Shell)
USA=0x1B32C-D: (Boo)
USA=0x1B32E-F: (Coin)
USA=0x1B330-1: (Thunderbolt)
USA=0x1B332-3: (Activated Boo)
USA=0x1B334-5: (???)

First byte is the 16x16-tile ID#.
Second byte is the palette assignment: 
30=White/Green/Black
34=White/Red/Black
38=White/Yellow/Black
3C=White/Cyan/Black

Level Number Text Offsets (uses normal table)

EU=0x1CA65, USA=0x1CBC9 - 1 (As in Battle Course 1)
EU=0x1CA69, USA=0x1CBCD - 2 (As in Battle Course 2)
EU=0x1CA6D, USA=0x1CBD1 - 3 (As in Battle Course 3)
EU=0x1CA71, USA=0x1CBD5 - 4 (As in Battle Course 4)
EU=0x1CA81, USA=0x1CBE5 - 1 (As in Mario Circuit 1)
EU=0x1CA85, USA=0x1CBE9 - 1 (As in Donut Plains 1)
EU=0x1CA89, USA=0x1CBED - 1 (As in Ghost Valley 1)
EU=0x1CA8D, USA=0x1CBF1 - 1 (As in Bowser Castle 1)
EU=0x1CA91, USA=0x1CBF5 - 2 (As in Mario Circuit 2)
EU=0x1CA95, USA=0x1CBF9 - 1 (As in Choco Island 1)
EU=0x1CA99, USA=0x1CBFD - 2 (As in Ghost Valley 2)
EU=0x1CA9D, USA=0x1CC01 - 2 (As in Donut Plains 2)
EU=0x1CAA1, USA=0x1CC05 - 2 (As in Bowser Castle 2)
EU=0x1CAA5, USA=0x1CC09 - 3 (As in Mario Circuit 3)
EU=0x1CAA9, USA=0x1CC0D - 1 (As in Koopa Beach 1)
EU=0x1CAAD, USA=0x1CC11 - 2 (As in Choco Island 2)
EU=0x1CAB1, USA=0x1CC15 - 1 (As in Vanilla Lake 1)
EU=0x1CAB5, USA=0x1CC19 - 3 (As in Bowser Castle 3)
EU=0x1CAB9, USA=0x1CC1D - 4 (As in Mario Circuit 4)
EU=0x1CABD, USA=0x1CC21 - 3 (As in Donut Plains 3)
EU=0x1CAC1, USA=0x1CC25 - 2 (As in Koopa Beach 2)
EU=0x1CAC5, USA=0x1CC29 - 3 (As in Ghost Valley 3)
EU=0x1CAC9, USA=0x1CC2D - 2 (As in Vanilla Lake 2)

You get the pattern? This relates to the LEVEL TEXT OFFSETS.
Which is shown in Time Trials and Battle Mode.

Level Text Offsets (uses normal table)

EU=0x1CB51, USA=0x1CCB5 - MARIO CIRCUIT
EU=0x1CB60, USA=0x1CCC4 - GHOST VALLEY
EU=0x1CB6E, USA=0x1CCD2 - DONUT PLAINS
EU=0x1CB7C, USA=0x1CCE0 - BOWSER CASTLE
EU=0x1CB8B, USA=0x1CCEF - VANILLA LAKE
EU=0x1CB99, USA=0x1CCFD - CHOCO ISLAND
EU=0x1CBA7, USA=0x1CD0B - KOOPA BEACH
EU=0x1CBB4, USA=0x1CD18 - BATTLE COURSE
EU=0x1CBC3, USA=0x1CD27 - RAINBOW ROAD

Only shown in Time Trials and Battle Mode and uses the LEVEL
NUMBER TEXT OFFSETS.

Text Placement Offsets (uses it's own table)

EU=0x1CA64, USA=0x1CBC8 - BATTLE COURSE 1
EU=0x1CA68, USA=0x1CBCC - BATTLE COURSE 2
EU=0x1CA6C, USA=0x1CBD0 - BATTLE COURSE 3
EU=0x1CA70, USA=0x1CBD4 - BATTLE COURSE 4
EU=0x1CA74, USA=0x1CBD8 - MUSHROOM CUP
EU=0x1CA77, USA=0x1CBDB - FLOWER CUP
EU=0x1CA7A, USA=0x1CBDE - STAR CUP
EU=0x1CA7D, USA=0x1CBE1 - SPECIAL CUP
EU=0x1CA80, USA=0x1CBE4 - MUSHROOM CUP 1 (MARIO CIRCUIT)
EU=0x1CA84, USA=0x1CBE8 - MUSHROOM CUP 2 (DONUT PLAINS)
EU=0x1CA88, USA=0x1CBEC - MUSHROOM CUP 3 (GHOST VALLEY)
EU=0x1CA8C, USA=0x1CBF0 - MUSHROOM CUP 4 (BOWSER CASTLE)
EU=0x1CA90, USA=0x1CBF4 - MUSHROOM CUP 5 (MARIO CIRCUIT)
EU=0x1CA94, USA=0x1CBF8 - FLOWER CUP 1 (CHOCO ISLAND)
EU=0x1CA98, USA=0x1CBFC - FLOWER CUP 2 (GHOST VALLEY)
EU=0x1CA9C, USA=0x1CC00 - FLOWER CUP 3 (DONUT PLAINS)
EU=0x1CAA0, USA=0x1CC04 - FLOWER CUP 4 (BOWSER CASTLE)
EU=0x1CAA4, USA=0x1CC08 - FLOWER CUP 5 (MARIO CIRCUIT)
EU=0x1CAA8, USA=0x1CC0C - STAR CUP 1 (KOOPA BEACH)
EU=0x1CAAC, USA=0x1CC10 - STAR CUP 2 (CHOCO ISLAND)
EU=0x1CAB0, USA=0x1CC14 - STAR CUP 3 (VANILLA LAKE)
EU=0x1CAB4, USA=0x1CC18 - STAR CUP 4 (BOWSER CASTLE)
EU=0x1CAB8, USA=0x1CC1C - STAR CUP 5 (MARIO CIRCUIT)
EU=0x1CABC, USA=0x1CC20 - SPECIAL CUP 1 (DONUT PLAINS)
EU=0x1CAC0, USA=0x1CC24 - SPECIAL CUP 2 (KOOPA BEACH)
EU=0x1CAC4, USA=0x1CC28 - SPECIAL CUP 3 (GHOST VALLEY)
EU=0x1CAC8, USA=0x1CC2C - SPECIAL CUP 4 (VANILLA LAKE)
EU=0x1CACC, USA=0x1CC30 - SPECIAL CUP 5 (RAINBOW ROAD)

Table (as in the Level Text offsets)

00 - 0
01 - 1
02 - 2
03 - 3
04 - 4
05 - 5
06 - 6
07 - 7
08 - 8
09 - 9
0A - A
0B - B
0C - C
0D - D
0E - E
0F - F
10 - G
11 - H
12 - I
13 - J
14 - K
15 - L
16 - M
17 - N
18 - O
19 - P
1A - Q
1B - R
1C - S
1D - T
1E - U
1F - V
20 - W
21 - X
22 - Y
23 - Z
24 - ?
25 - .
26 - ,
27 - !
28 - '
29 - "
2A - cc
2B - *blank*
2C - *blank*
2D - *black square*
2E - :
2F - *blank*
30 - L
31 - A
32 - P
33 - T
34 - IM
35 - E
36-DF - I dunno
E0 - MUSHROOM CUP
E1 - FLOWER CUP
E2 - STAR CUP
E3 - SPECIAL CUP
E4 - MARIO CIRCUIT
E5 - GHOST VALLEY
E6 - DONUT PLAINS
E7 - BOWSER CASTLE
E8 - VANILLA LAKE
E9 - CHOCO ISLAND
EA - KOOPA BEACH
EB - BATTLE COURSE
EC - RAINBOW ROAD
ED-FF - I dunno

This selects an offset from an offset
category. For example, if you change E4 in 1CA80 to EB,
it will show BATTLE COURSE 1 instead of MARIO CIRCUIT 1.

and if you change E0 in 1CA74 to EC, it will show
RAINBOW ROAD instead of MUSHROOM CUP. 

--Information found by NES Tea, reposted on acmlm's board by Ok Impala!