What’s y’all preference for fishing 3.5 to 4” swim baits ( 1/4-3/8 jig heads) in 6-10’ of water for largemouth. 

If baitcast what line size type?
Same question if spinning.

I have 7’ rods in both. 
Mainly trying to dial in line size and type. 

That’s a tough range because it also depends on the weight of the plastic for me and the gauge of the hook being used. Not all swimbaits are made the same, they may be the same length but one may be much beefier/thicker, so heavier, than the other. Am I overthinking and over complicating? Probably. 
 

If these are light wire hooks then I’d go go with a 7’ M spinning rod, 1/4 oz -5/8 oz rating or around there. I throw 4” easy shiners on a 1/4 oz ball head on that setup. I wouldn’t be afraid to step it up to 3/8 oz if I needed to with similarly sized swimbaits on light wire hooks . I’m using a 15# braided mainline to 8# mono. 
 

Now if it was a thicker plastic say like an XZone Swammer, especially the 4” one, and/or a heavy gauge hook, then I’d for sure step it up to a MH baitcasting rod, 3/8-1 oz range. 33mm diameter mono or fluoro for me. That may be 15# or 12# depending on the brand. 

52 minutes ago, SC53 said:

What’s y’all preference for fishing 3.5 to 4” swim baits

Open water? A minefield of Lily pads nearby?

6 minutes ago, PhishLI said:

Open water? A minefield of Lily pads nearby?

Sorry. Open water over shell beds or underwater grass. Being in Florida, there’s always a chance for a big fish too but probably 2-4 lbs on average. 
Jig heads would be heavier gauge due to the possible big fish scenario. 

I would use 10-12 pound fluoro.

12# Big Game 

Small swimbaits are swimjigs, any MHF Jig & worm rod works good with 1/4-3/8 oz jig jigs. Same line you would use for jigs & worms for that weight range in light to medium grass cover.

Tom

Tom, pretty much what I was thinking too. 
Only question is mono or flouro.
I like and use Big Game but think flouro might give me a little more strike detection and hook setting ability due to the lower stretch in the deeper open water.