Triumph Sports Cars

engine swaps and other performance upgrades, plus "factory" V8s (Stag and TR8)

Go to Thread: PreviousNext
Go to: Forum ListMessage ListNew TopicLog In


maddmonkey187
Gadge Spillman

(2 posts)

Registered:
09/08/2019 05:48PM

Main British Car:


Rear end for my 3.8 and t700r4 transmission tr7
Posted by: maddmonkey187
Date: September 08, 2019 05:59PM

Ive just started rebuilding my tr7 and ive rebuillt the 3.8 buick engine and t700r4 tranny i know im going to have to get a custom druve shaft but whats the best rear end for this build?anybody else done this build with johns cars swap kit?


TR8Driver
Darrell Walker
Vancouver, WA, USA
(5 posts)

Registered:
08/23/2019 07:59PM

Main British Car:
1981 Triumph TR8, 1966 Triumph TR-4A 3.5 Rover V8, 2.1 wet liner 4 cyl with super charg

authors avatar
Re: Rear end for my 3.8 and t700r4 transmission tr7
Posted by: TR8Driver
Date: September 08, 2019 08:06PM

What kind of power are you expecting?


maddmonkey187
Gadge Spillman

(2 posts)

Registered:
09/08/2019 05:48PM

Main British Car:


Re: Rear end for my 3.8 and t700r4 transmission tr7
Posted by: maddmonkey187
Date: September 08, 2019 10:41PM

Just wanting to drive around town and some highway driving nothing like something i would take to the track


tr8todd
Todd Kishbach

(366 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: Rear end for my 3.8 and t700r4 transmission tr7
Posted by: tr8todd
Date: September 23, 2019 07:22AM

The stock 5 speed rear end should handle the power. The TR8 made 150ish HP, and there are plenty of them running well over 200 hp thru the stock rear end. If you have an older coupe with a 4 speed rear end, then forget about that. Those things were junk. I'm a fan of the Ford 8.8 rear ends. If you can find a mid 80s Fox body Mustang GT, then you can get away without narrowing it. Later Mustang 8.8s just kept getting wider. I like the Ford Explorer rear ends. You only have to narrow one side. The long side is close to 3" longer than the short side. Cut the long side down to match the short side and install another short axle. They are heavier and stronger than the car based 8.8s, but the two TR8s I have them in now both make over 400 hp. I have also seen Dana 44s and even a Toyota truck 8.4 rear end used. The Toyota rear end is whats used in Legends cars, so its gaining a following. The Dana rear end seems to be getting harder to find. They were everywhere 20 years ago. Every Postal Jeep mail carrier had one. The Ford is common, cheap, has loads of aftermarket parts, gear ratios, and its easy to rebuild.


tr8
Paul MacDonald
Canada
(35 posts)

Registered:
10/25/2008 04:07PM

Main British Car:
TR8 Coupe Rover 4.0

Re: Rear end for my 3.8 and t700r4 transmission tr7
Posted by: tr8
Date: September 23, 2019 09:18AM

"mid 80s Fox body Mustang GT, then you can get away without narrowing it." Todd, what wheels would fit with this rear axle and under stock fenders?


tr8todd
Todd Kishbach

(366 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: Rear end for my 3.8 and t700r4 transmission tr7
Posted by: tr8todd
Date: September 25, 2019 02:59PM

Bolt pattern is 4X108. You would need an offset higher because this rear end is slightly wider than stock. Something in the +35 to 40 would be ideal. Lots of room in the back, so you don't need to be perfect. Just don't stick out so far you hit the fender lips. I know of a few running around that have redrilled front hubs to 4X100, then wheels with a dual 4X108 and 4X100 bolt pattern were used. First time I saw this rear end at its stock width was on Scott Holton's TR7 ITB race car. Glen has this rear end in his Ford 302 powered TR7. He bought an 86 Mustang GT for his donor car. Used the engine with a set of aluminum heads. Built a custom tubular subframe to mount the Mustang power steering and the 302. Installed a later World class T5 and the Mustang rear end. Shortened the driveshaft to fit the TR7. He is running dual pattern aftermarket wheels that came on a Miata he bought and sold.


tr8
Paul MacDonald
Canada
(35 posts)

Registered:
10/25/2008 04:07PM

Main British Car:
TR8 Coupe Rover 4.0

Re: Rear end for my 3.8 and t700r4 transmission tr7
Posted by: tr8
Date: September 25, 2019 04:47PM

perfect. thanks Todd



Sorry, only registered users may post in this forum.