wirring 4 gauge to a 8 gauge amp post

Currently i have an infinity basslink in the trunk of my 02 chrysler concorde lxi witch was given to me by one of my friends. i have 4 gauge power wire, and 4 gauge ground wire, wired to the amp. infinity basslink has a 30 amp fuse and is rated at 200 watts rms going to the enclosed 10inch sub. the basslink calls for 8 gauge wirring. i have wirred with 4 gauge for future aditions. my problem is that the rig i made to wire up the amp keeps comming loose from the ground. i took a 4 gauge ring terminal and cut off half of the ring to make it like a hook and inserted it in a 8 gauge ring terminal and crimped it in place. i dont want to change the power and ground down to an 8 gauge set up.

if i use a distribution block to step down to an 8 gauge. one for power and one for ground will this affect anything?