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I am seriously thinking about replacing the 4-speed in my 67 GT350 with a 5-speed. I'm having a stroker 347 built that will probably make about 325-350 hp at the flywheel. That puts me right on the borderline of what a "world class" T5 can handle. I figure the T5 will be okay if I don't abuse it too badly but I would rather have a little overkill like a Tremec.

I'm keeping the original bellhousing/clutch linkage setup.

I see two possible options: (1) T5 with adapter plate and shorter driveshaft yoke (maybe have to shorten the driveshaft) or (2) Tremec with a shortened input shaft (no adapter plate needed, no driveshaft shortening).

I've done a lot of research on the internet and it still is not clear as to which of these combinations will fit better. I do NOT want to have to cut the tranny tunnel in any way. Maybe shave the edges of the existing shifter hole but that's about it.

Either one of these options a true "bolt-in" without any serious massaging necessary?

And please, no replies about "I can't believe you would do that to a Shelby". A 5-speed will allow me to drive the car out of town and isn't that what we all want to see - a Shelby out on the road?
 

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Send a PM to 2bav8, he's done both in his car. From what I understand is that the T5 fits much better. The Tremec needs to be dropped more in the rear to fit causing drive line angle problems. This is the route 2bav8 went but reports no problems. I also remember a post where someone had their fan touching or hitting the radiator after lowering the rear of the Tremce to fit in the tunnel. If you stick with the T5, one thing I've found out that does wonders for keeping a T5 together is to replace the stamped steel reatainer on 5th gear with a billet. From what I've read, under heavy loads the steel reatainer deflects and loosens up causing failure. The billet retainer doesn't increase torque capacity, just keeps it together. One guy I spoke with here on the forum who rebuilds T5's said he's never had a T5 come back with the billet reatainer. Like I said, 2bav8 can give you 1st hand info.
 

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I'm sure the T-5 Summit sells as "world class" has this steel retainer, plus it has the more useful 1st gear ratio.
I think to hide the 5 speed, you will need to adapt the correct shifter to the stub, instead of using those current billit ones.
 

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I believe what Tom is talking about is an internal retainer, not the input shaft collar/retainer that is steel on the T5z's (as Summit sells). As far as shifter handles go, several places sell stock looking handles. I prefered a Hurst handle and ball for a period correct performance look. see http://forums.vintage-mustang.com/forums/photopost486/showphoto.php?photo=886&nocache=1. There are some good reviews on www.stangnet.com for shifters. The Steeda Triax and Pro5.0 seem to get the best reviews.

I am glad to hear you are driving your Shelby. You will love the performance gain you get with a 5 speed and it is nothing that is not reversable. :highfive:
 

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Well, I didn't make any mods to install my Tremec.
I did shim the back up as far as possible and IMO the angle is about the same as when I had a T-5 in the car.

Having had both transmissions in my car, I am much happier with the Tremec.
 

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To my knowledge, the tranny tunnel on a '68 and '69 are the same size. I didn't make a single modification to my '69 when I put the Tremec in it. I did have to shorten the driveshaft, but that was it. I didn't even enlarge the shifter hole, but the shifter is pretty close to the passenger side of the shift hole.

The gearing in the Tremecs is better than the T-5's. Especially with the power that you're planning to build, I would go with a Tremec.
 
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