Which is the best cracking mode?

[ly88888]

My password format is:
abcd4dcba
abcde5edcba
abc3cba

The starting part is a random string+String length+The string is inverted as a whole
(The translation I used may not be very accurate)

My idea is to crack with rules,
wordlist:abc
rule:fD4
Run the results: abc4cba

but,This requires preparation of a huge amount wordlist

Do you have any better suggestions?Thanks!