73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: fitz on January 06, 2009, 09:47:03 pm

Title: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: fitz on January 06, 2009, 09:47:03 pm
  I planned to run a 14 bolt 9.5" s.f. in my truck but as I look around this site I am second guessing myself. Is it worth stepping up to the 10.5" f.f.  The drivetrain will be a 400 S.B. with TPI, turbo 350/205, 4.11 gears with a 4" lift and 33" tires. It will be used as a DD/tow rig and will not see any serious 4 wheeling any time soon.
  Any thoughts on the 9.5" vs. 10.5" for a street driven truck? What would you recommend for a posi unit? I was thinking of an Eaton but an open for suggestions.    Thanks.
                                                                                            Fitz
                                                                                             
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: Blazin on January 06, 2009, 10:23:40 pm
Hands down a fulll floater!
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: yellowk20 on January 06, 2009, 10:28:06 pm
for your app the SF will be fine but if you have to buy the axle just pony up and get the FF
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: VileZambonie on January 07, 2009, 05:05:54 am
The ff is better but the 14 bolt sf is still a strong axle.
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: oldwhity on January 07, 2009, 06:44:35 am
In my opinion, the sf will be more than sufficient like Yellow and Vile say since your probably not doing any heavy wheeling. But if it's as easy as swapping axles like Yellow says and not a huge cost difference than I would keep it an option. Just my 2cents.
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: Blazin on January 07, 2009, 06:47:48 am
my $.02 is why not do it right the first time. If a little is good than more must be better! lol
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: VileZambonie on January 07, 2009, 09:32:18 am
I wouldn't stray away from either if you catch a good deal on one. I have SF in my K20 and the FF in my Mutt.
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: yellowk20 on January 07, 2009, 10:18:08 am
the SF is a good axle I've never heard of anyone breaking one there comparable to a Dana 60 in strength maybe even a bit stronger.
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: fitz on January 07, 2009, 12:51:10 pm
  I already have both axles. My concern is that the F.F. in the truck now is out of a dually cab/chassis and has huge brakes on it. The truck had 44" tires on it and it stopped fine. When I put on a set of 35"s the rear brakes lock up fairly easy.
  The truck has a Wilwood adjustable proportioning valve that I will try adjusting once the roads around here are dry. I have a spare S.F. and I was thinking I might be better off with the smaller brakes if adjusting the proportioning valve does not solve the problem.   Thanks
                                                 Fitz
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: Blazin on January 07, 2009, 01:53:44 pm
If its from a cab and chassis it is narrower than the front end. Must track funny? As far as the brakes locking up if they are adjusted correctly, and the valve is adjusted they shouldn't.
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: fitz on January 07, 2009, 05:13:35 pm
 I never noticed any tracking issues. With the 44's the truck drove so bad that was the least of my problems. Now with the 35"s it seems to track alright but that may be sheer luck due to the mismatched rims. Front (15" x 8") Rears (16.5" x 9.25").
 I'll pull the rims and measure the WMS on the rear and see what I have. Thanks
                                                                                                                                Fitz
                                                                                                                       
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: Blazin on January 08, 2009, 12:49:15 am
The cab and chassis rears you can barley get your wrench between the springs and the backing plate to bleed the brakes.
Title: Re: 14 bolt 9.5" s.f vs. 10.5" f.f.
Post by: cracker0169 on January 15, 2009, 10:51:42 pm
that looks like a C&C axle. I say do it right and find a FF that has the regular width. You may even get lucky and score one with a Detroit in it!