I first want to start by saying, this is a awesome site! So much info its great!
Now I'm posting because I'm ready to put more ponys under my hood. I was out muscled by a
2015 chevy Malibu. Really! But at 155hp what do you expect. Lol anyway I plan to get a trick flow
Bolt on that claims 350hp but first I want to upgrade my differential to a 8.8 positraction or more specifically Torsten diff with a 31 spine axle and 5lug conversion (front and rear) will a 8.8 rear fit directly on my 88 sport if ordered from rock auto? Will I have to change axle housing? Is my 88 sport 8.8 posi anyway? Or is it just the TC
88 Sport should have a 7.5" rear. You can't put 8.8 guts in a 7.5 rear housing. You need an 8.8 rear housing to run 8.8 differential and gears.
Check out coolcats.net the 88 sport was similar to an xr7 of the same year. A 5 lug swap can be done pretty cheaply with sn-95 mustang junk.
Look at the diff cover. If its more of a rounded square, its a 8.8" diff. If its flat top and bottom and found on the sides, its a 7.5" diff.
If you are going to switch over to five lug then just get a rear end out of a 94-98 Mustang GT. You might get lucky and find one with the optional 3.27 gears and a traclok i.e. limited slip posi. The axle code on the tag would need to be 3L27 for that option. I would suggest this path as it gets you five lug, disc brakes, a decent rear axle gear, limited slip posi, and you can probably get it for less than $250 brake to brake if you shop around. The 94-98 SN95 Mustang rear is the width you want as the Fox Mustang rears are narrower. I have the Fox Mustang rear in my car and had to hunt for wheels with the right offset.
I would just opt for the SN95 front five lug conversion at the same time of which you would want the 94-95 spindles for a stock K-member car. Utilizing the 96+ spindles increase your chance for bump steer issues but some have had luck with them. Also, run the 99+ front calipers as they are dual piston calipers and brake a lot better than the 98 and down single piston calipers. You have to mod the 98 and down spindles but it is a very minor mod (do a search as it has been covered a lot). You will then need to install a 93 Cobra booster and 93 Cobra Master Cylinder to complement the brakes. I would also suggest stainless steel braided lines.
All of the braking stuff has been covered on here several times so search away.
I located a 88 TC rear 8.8 with disk brakes. Is this a direct bolt on to my sport?
Yes. If you are planning on converting to five lug I would just go straight to the SN95 8.8 rear. The 7.5 under the car will take some abuse as long as you do not put slicks on it.
I cannot remember if the TC rears are set up like the Fox Mustang and SN95 cars with regards to the brake lines. On my '83 the hard brake line from the body ran down the passenger side and terminated just above the area where the lower control arm attaches to the body of the car. From there a soft line attached to the body hard line and then went over to the passenger side axle tube on the rear and it had a distribution block on the end of it for the hard lines over to the slave cylinders. The Fox Mustangs and SN95 Mustangs body hard line goes over towards the pinion of the rear end and terminates into a fitting. From the fitting a soft line is attached which goes over to the rear end and then hits a distribution block for the hard lines over to the slave cylinders or to flex lines to the calipers. You can see the body brake line goes to the rear end on the Fox 5.0 Mustang /SN95 Mustang set up here:
http://www.americanmuscle.com/87-98-rear-diff-hose-cust-install.html
I been trolling through old posts and got some info about the rear swap and everything seems like a direct swap but does anyone has anything to add, that will make my swap smooth,if so please by all means post.....also will the conversion from drum to disk be an issue and if so what will be the issues?
If the Trick Flow kit comes with a cam, you'll need Mass Air. The stock ECM can't manage a big ol Trick Flow cam at all. Also, watch for piston to valve clearance as the stock pistons are flat tops.