Clutch question
 

Could use some advice on a future(sooner than later) clutch purchase. Looking for a clutch that will hold well under my mods while towing a 4500lb boat with 3500lb camper in the bed. Quick recap of the mods are open style air filter on factory air boot, Banks brake, 120hp injectors, edge comp box, 5 inch exhaust and 35" tires.
I see there are clutch kits that have 12.25 and others are 13.00 and have different shaft dia. Which one is stock? Also i see that a few kits come with a fly wheel, that the way to go ?
Anyone use a centerforce? Suggestions welcome.
Thanks in advance.

U need to call Haisley machine order a dual disk street puller with the 1 1/4 input shaft billet would be wise also. I have the same clutch that I just rebuilt from 5 years of pullin on the track every week end n pullin 20,000 lb trailers durin the week. I'm a farmer so I'm hard on stuff lol but if u don't pull u won't ever have to replace it