[jpg69bird]

Anyone ever try to put a four speed into a 72 GP? The 69's - 71's were offered with a manual, so I would assume the attachment points are there for an installation into a '72, including the trans support. I have a Muncie four speed from a '69 Lemans with a Hurst shifter collecting dust, that I would like to put into a '72 SJ 455. The current motor/trans are not original, so originality is not an issue.

Would the console need to be swapped? What kind of cutting would be expected?

Any info to help make this easy would be appreciated.

John

[marxjunk]

console the same but the top plate is diff

i1 hole in the floor for the shifter

need a 70-72 GTO shifter for correct look

you will never find the frame brkt for the z-bar..you'll have to make that

need a few pieces im not mentioning..but its very do-able and pretty easy really..with GM parts

[rexs73gto]

The frame bracket is the same for the GTO as the Grand Prix so the frame brkt. will be easy to get a hole of. The parts needed for the swap are all the same for the GTO as the Grand Prix so anything you need can be gotten easy. Go for the swap it's an easy job to do. The only thing you may have to get a different driveshaft depending on which trans you use. The M-20 & M-21 use the yoke for a turbo 350 & the M-22 & T-10 use the yoke for the turbo 400. The crossmember also may have to be moved but the hole are already in the frame to move it where you need it. Same with the Z-bar brkt. the hole for the placement of it will be already there for the brkt. almost directly under the brake booster. Then you'll just need the Z-bar which again is the same as the one for an A-body , Lemans, GTO. Next to make it look correct you'll need a sterring column for a floor shift car which again is the same as all the A-body cars. Just in case your G/P is a column shift car.

[mrgto69]

Rexs73gto: as mentioned in marxjunk's reply... the frame bracket is NOT the same as GTO. The console top plate, ash tray & frame bracket are only found on GP manual trans; everything else can be found in reproduction.

[jpg69bird]

Thanks for the quick replies. I'll be amassing the parts over the winter for a springtime install.

This is a console car, so I don't have to deal with those issues.

Any more info will always help.

[rexs73gto]

I guess I should have said the frame brkt. is the same as MY GTO. The brkt. for the 73 GTO is the same one that they use on the G/P's. I have I think 2 hanging on my peg board in the garage.

[Keith Vrabec]

69-71 GP bracket is different because the engine is set back about 5 inches...GTO has engine mounts on the cross member and the GP has them behind the cross member. the gto z bar hits the frame where it is higher on the kickup to the front suspension. the gp has it farther rear on the frame making it necessary to be much taller than the gto tab. SO gm came up wth this cheezy bracket made from stamped steel and would just break and crack with the pressure of a decent clutch assembly.

So the solution is to build a bracket to accept the z bar out of sheet steel, and gusset it so it doesn't flex.

There is a great example of what you need to do on the race car. Thick steel, two gussets, a very sturdy support.

third pic shows about where your z bar will hit inrelation to the frame. see the three holes in the frame to take the bracket in a triangle pattern

last pic is approx. location of a GTO welded tab. will be much shorter and sturdier

BUying a correct (junk) bracket will cost $200 or so and if you don't have a restoration, you shouldn't use it. BTW most stock brackets already have been repaired, usually another plate of steel added to them for support and for crack repair. Look at the stock bracket in the second pic it's likely broken.

FInally, if your GP with stock bracket won't adjust the clutch properly, it's the bracket, cracked at the top where the z bar connects.

Not a lot of difference from the 69 to 70-72 shifter handles, 69 will work, might hit the radio if you powershift to third though. But you can do that with a 70-72 handle as well

[jpg69bird]

Thanks Keith, I knew if someone had info on 4 Speed GP's it would be you. Thanks also for the pics.

Are there any dimensional drawings of the blueprint part from the 69-71 GP? I can easily design and fabricate something beefier from scratch.

[Keith Vrabec]

Best way to do it is to take the driver inner off. place the z bar on the block (trans must be installed!) then tack a piece in place. then make sure it's in the right place by having someone operate the pedal and make sure it is working properly. There's a fair amount of room for error since the z bar is on a swivel on the block and the bracket. (Look at the picture of the stock bracket..that clutch still worked with that much deflection...) But not that you want the error...just make the tab, then add gussets after it's in place.

Any welder dude would find it a pretty easy fabrication.

Someone did find a blueprint somewhere....someone in Michigan, not Andy....got a copy but it was so faint I couldn't read it.

[Keith Vrabec]

I can give yo usome locating measurements off the junker in a few days...how far off the frame and how far from the inside of the frame rail. I can install the bracket on the 70 or the 71, both front ends are off those cars, and take the measurement from them. WIll get you in the ballpark.

Probably should just make a pattern for you and the rest of the world while I'm at it....

[Matt Meaney]

like others have said, your better off making one of your own. here's a pic of a nice original, along with a welded up one.

[Keith Vrabec]

Amost makes sense to replace the original even on a restoration, or tack it down to the frame with a gusset anyway, for reliability.

[wbulick76]

Or McLeod makes a really cool hydraulic pedal set up that you can then use with a hydraulic throw out bearing if your not going for originality. I'm thinking that's the route I'm going to take. I was looking at it at SEMA and it's really pretty cool.