exatly how complicated is the conversion any ideas, tips, tricks,

thanks, matt

 

Depends on your abilities.

The hardest bits would be the pedal assembly (anything to do under the Vette dash is always fun) and mounting the frame bracket for the Z-bar (aka bellcrank).

The list of parts for the conversion is as long as your arm; even includes a new console shift plate.

 

I have done it twice, on a 73 and a 80. I found it fairly easy to do as long as you gather all the correct parts. Pedal assembly goes in easy once you remove the dash. The z bar support must be put on the frame in the proper location. This support bracket can be bought new at a lot of Corvette supply dealers. On 80 and newer C-3, this bracket bolted to the frame and the automatic frame has the 2 holes already drilled. I believe you could bolt the bracket to a 79 or older frame if you do not have welding equipment, although you would have to drill 2 holes in the proper location, drilling these holes might be a little easier than welding if the body is on the car. If you can weld, the bracket was originally welded on the 79 and older cars. Everything else is basic bolt on, except you will need to cut a hole in the console area for the shifter. If you can look at a 4-speed car and take some measurements, the hole can be cut fairly easy. If you really want to make a improvement, install a aftermarket 6-speed transmission while you are doing the conversion. I have Richmond 6-speed in my 1980, it is pretty much a bolt in to replace the factory 4-speed, only the transmission mount has to be modified. It is actually a fun project if you do not mind spending a little time and a bit of money. Good luck.

 

mounting the pedal assembly is by far the most difficult part of the conversion. there are four bolts that support the assembly, two can be accessed under the dash, and two are in the windshield trough. i'm sure that the left dash and steering column will have to be removed in order to install the pedals. both conversions that i've done were in conjunction with total rebuilds, so i can't say for sure someone couldn't reach up under the dash, but i don't really see how it would be possible. changing the p/b booster would be easy in comparison.
the rest of the conversion is straight forward, and well within the abilities of anyone that has some mechanical experience-and would be a nice starting job for anyone that is a novice.

 

I have done many of these conversions and you do not need to remove the dash. The steering column yes. It is a little bit of a struggle to get the pedal box out but take your time and it can be done. The frame connection for the Z barcan either be welded or they now offer a bolt on kit. I have welded a few brackets, never done the bolt on. I have installed a few hydraulic systems which remove the whole Z bar assembly. A little more expensive but it is a nice system. You already have a removeable crossmember which makes the swap easier. You will need all the components from a 4 speed car. The hole in the tunnel, just measure carefully and start out small. You can always go bigger with the hole, real tough to make it smaller.

 

Here's a link to a paper I put together as I added the clutch pedal during conversion to a T5 in my '78:

Pedal Assembly Removal

It is a .pdf file you can download. Includes photos, images from the Assembly Information Manual (AIM), and a detailed procedure for steering column removal.

As several above have said, pedal assembly removal and reinstall is the toughest part of the job. Hope this helps.

Jerry
78IndyPace

 

Agree the pedals are the most difficult part. Don't try to re-invent things. Stick with OEM/OER parts for pedals, clutch linkage and mount, including the correct Corvette specific fork. You can use the lower shifter boot as a template to accurately cut the hole in the trans tunnel. Follow AIM instructions for clutch pedal adjustment. IMCO you should forego the stock shifter in favor of a Hurst Comp Plus. Done well, this will be one of the best mods you'll ever do.

FWIW, if you're doing a small block and going with a 153 tooth flywheel, I've got a GM bell available.

 

News flash, everybody read this and save yourself a lot of grief!!!! On a auto to manual conversion, the bracket way up in the dash that the automatic brake pedal hangs from is the same bracket that a 4-speed car would have. You do not have to remove this bracket for the conversion. Simply pull the retaining clip off of the pivot pin, slide the pin out, and the auto brake pedal will come out. (You also must remove the plunger that depresses the master cylinder.) You can now put the new clutch and brake pedal in the same bracket. If you look at the old brake pedal from the automatic, and compare it to the clutch and brake pedal, you will see why this will work. Also, the auto brake pedal is the same as the 4-speed brake pedal, except for the pad size where your foot would press. You could take the auto brake pedal and trim the pad and turn it into a 4-speed style (narrower pad) pedal if you cannot find a 4-speed style pedal. You would also need to shorten the round part at the top of the auto pedal so both pedals would fit into the bracket. I have done this on a 73 and a 80, and believe me, you do not want to take out the bracket if you do not have to. Good luck.

 

I agree with Buddy1980 as far as just adding the clutch pedal.

However, a standard item in factory 4-speed manual installations is the "clutch neutral safety switch". This switch is normally open and allows starter motor engagement only when the clutch pedal is depressed. For me, this safety feature is mandatory. Years ago we had a VW diesel with a manual trans but no such switch. The car was in gear and my daughter forgot to depress the clutch pedal when attempting to start. The car's front end ended up in our family room! Nobody hurt, but not pretty. Happened fast.

If you think this switch might be important to you, IMO the switch cannot be installed without removing the pedal assembly as several have discussed above.

Here's a link to another paper I wrote as I set up my brake/clutch pedal assembly and installed the switch:

Clutch/Brake Pedal Assembly Mods

It clearly shows the switch I'm talking about, which is available from any 'Vette parts vendor. Hope this helps.