Currently my 67's engine is a late 80's 5.0 stroked to 347 c.i. High compression pistons and an E303 cam. Now I want to replace the C4 tranny with a manual.

Originally I wanted a 5 speed but with T5 not rated above 350, and the TKO needing the channel raised, I started looking at Top Loaders.


What do you guys think, I personally want a 5 speed for the OD for some better highway miles but I want your guys opinions?

 

TKO, it will fit without raising the tunnel, maybe some hammer work and shimming of the mount to get the pinion angle correct. It's basically like a Toploader with an extra gear and it's more efficient.

 

TKO
-Drop Mounts
-Some massaging to the tunnel
-Be sure to keep the crossmember as high as possible (shimming as indicated by fellow poster)
-Low profile shifter

 

Keep in mind, TKO's don't like to be shifted much above 6k rpm. The fox body guys road racing their cars are finding this out. On the street it's probably not going to matter. But if it's a high-winding engine that you plan on open tracking in the future, it's something to keep in mind.

 

Does any transmission like to be shifted above 6000 rpm?

 

The Tremec sheet literally contains the following statement, just to add to what starfury mentioned:

"Do not attempt to shift the transmission when the engine is revving over 6500 RPM's."

 

A properly built T5 will shift at 7k+ all day. You can get Astroperformance or American Drivetrains (I think that's their name) to build you one for the price of a new TKO. If I ever put a 5sp in my fb, that's probably the route I'm going to go.

The road race guys are finding out that their TKO's are locking up when shifting at high rpm's. They're just not meant for that kind of use. They're basically improved toploaders with internal shift rails and an extra gear (literally, Tremec bought the toploader design from Ford). They're designed to hold against torque from a stroker or big block, but not for road racing.

Another option is the Richmond 5sp that was introduced at SEMA. Supposedly a near bolt-in that will hold monster torque. Expensive, though.

 

TKO's will shift fine at 6,500. They can be easily modified or bought modified to shift at much higher rpm. They're good for road racing since they won't fail the endurance test. But if you have something that you're road racing where you need to shift at 7k or above, you should really be looking at a dog faced setup instead of a standard synchro.

The Richmond 5spd will be a beast to shift. The gear clusters are freakin huge so they hold a lot of rotating inertia. Everyone who bought one has complained about the shift effort at higher rpm. That's why I went with the TKO over the Richmond.

My TKO shifts fine over 6,000rpm, never had any issues with it. Though it does have room for improvement in some areas such as shift lugs, mainshaft thrust and blocker rings(I'd like to see someone make a carbon faced blocker ring setup for them).