Pollock. What size shad?

I'm fishing inshore, from my kayak, around the kelp beds.

I have been having some great sport on small shads approx. 3.5".
I have been catching fish up to 6-7lb.

Well, i'm pretty sure there are bigger fish out there.
I bought some shads in 4" size(Alot thicker than 3.5" lures)
I bought some in the 6" range ( I could be wrong, but I think these are too big??)
I bought some jelly worms
And some large eddystone eels ( With the smallers ones i'm pestered all day with small fish or mackeral).

What do people think would be my best bet, to traget the larger fish in the area?

6 inch ones should be fine if your aming for the big ones also give grubs a try they look like firetails just shorter and thicker

I always used 6" but this year I saw someone using 4" and was landing big pollock so I've started using 4" myself with great success even managed 10lb on one....

That is a specimen pollock. 10lbs, from rocks or boat.

I think it might be 12lbs for a specimen.

Kev