Originally Posted by 351cid
i have never really checked into the tremec boxs
do they use the same fit up as toploader? - clutch/ bellhousing/ tailshaft.
Unfortunately there are a few changes required if replacing a toploader.
The TKO input shaft is about 1/4" longer. 3 options here.....
1. Dellows Automotive make a custom alloy bellhousing for $450.
2. Castlemain Rodshop makes a spacer that goes between toploader bellhousing and gearbox $250.
3. Mal Wood can mahine down the input shaft so you can use original bellhousing. Mal recommends this option. Tremec talk about warranty issues with this, but if you buy from Mal, he'll give you a warranty, so no worries.
I went #1 but had major front uni rattle issues. I though it was the bellhousing so went to option #3. Problem still there (bellhousing was fine)!! Finally found the issue was caused by a high angle between the gearbox and driveline (about 5*). Where the cross member bolts to a TKO, those tabs are 1" higher on the extension housing which makes the bos sit lower. A $5 homemade spacer and it was fixed. My car is lowered 2" which makes driveline angles worse.
The TKO has a 26 spline input shaft so you'll need a new clutch disc (toploader = 10 spline).
Output shaft is 31 spline. My box came with a 1350 yoke so you may have issues getting unis to match. Mal helped me out here....told me to turn my tail shaft around backwards and then he told me what size unis to get. There are "stepdown" ones available which have 2 different size uni caps.
My driveshaft ended up being about 1 1/2" too short. I just got a whole new one made up.
The Ford speedo senders fit, just need a Tremec cog to fit on.