66 GTO Upgrades

[DRD57]

I have a potential customer who wants me to take over his GTO project. The last shop went out of business and basically ripped him off for about $12k in parts that got paid for but never delivered and work that was paid for but never done. It's been sitting for a couple of years because he hasn't trusted anyone to work on it since the last shop turned belly up.

I went to see it this evening and the work that has been done looks good. The chassis has been powdercoated, the front suspension is all rebuilt, the rear axle was supposedly rebuilt (I didn't check that yet). He got a correct 389 from a Pontiac engine guru in the Chicago area. That's upside down, wrapped in shrink wrap, on a pallet in his garage. The body work and paint has been done but the body is still sitting on a cart covered in a car cover and numerous moving pads to prevent damage.

The car will be mostly stock but with some concessions to driveability, comfort and style. The color is not an original 66 GTO color and the interior will likely be a different color than original but, in the original pattern. He wants a manual transmission and I've talked him into one with overdrive. He also want to upgrade the front brakes to disks.

Are there any tricks to putting a 5 or 6 speed into a 66 GTO?

How about disk brakes? Is he going to have to buy a "kit" from someone like Stainless Steel Brakes or is there a junkyard swap that would work. I heard that S10 disk brakes would work but have no faith that the source actually knew what he was talking about.

[enjenjo]

No tricks on the trans swap, there is plenty of room under the floor. You may have to modify a bit of the floor to clear the shifter. If it has a console, you may have to modify it for the shifter position. Watch bell housings, there are two different sizes for the bearing retainer bore, and a 66 had the trans rotated 5 degrees clockwise to move the shifter towards the center of the car. Not all BOP bell housings are the same.

There are several ways to go on the brakes. The simplest is to used spindles and disc brakes from a 69 to 72 GM A  or G body, it will all bolt right on. The master cylinder is a bolt on too. Can't find the spindles? An easy modification to the stock spindle, and you can use the 69 to 72 brakes on the stock spindles. Outside of the spindle, the rest of the parts are available from several sources.

If you want to incorporate better handling at the same time, you can use 73 to 76 A or G body, or 70 to 82 Camaro spindles by changing the lower ball joint to an aftermarket modified ball joint, and using a shorter upper A frame. This is usually referred to as a tall spindle conversion. Parts are available from Global West among others. This has brakes that are similar to the 69 to 72 brakes, but the tall spindle has a better camber curve for hard cornering. You can also do this with a 71 to 96 B body spindle, and by using a 94 Camaro rotor you can have the big 12" brakes, 4 3/4" bolt pattern, and better handling.

Using the modified ball joint mentioned above, you can use a S10 spindle and brake setup, same as an 83 to 91 Camaro brake, but it is even shorter than stock, which increases camber on turns, and the turn radius is limited by the shorter steering arm.

The last choice is to used a bolt on aftermarket spindle that is set up for a 2" drop, and accepts all the S10/ 83 to 91 Camaro / 78 to 87 A and G body brake hardware.

[Deuce]

Neat information ...
I am faced with somewhat the same problem, my brother has his first car ( 66 GTO ) and it has sat since 1976. He got it in 1971 as a one previous owner car and drove it for 5 years until it needed some work.



Photo from 1972 or 1973 ...

He wants it back on the road now with the brake upgrades and a few other improvements. At least his is all complete and original ... never messed with. It has been stored inside for over 30 years  

[DRD57]

You can also do this with a 71 to 96 B body spindle, and by using a 94 Camaro rotor you can have the big 12" brakes, 4 3/4" bolt pattern, and better handling.

The last choice is to used a bolt on aftermarket spindle that is set up for a 2" drop, and accepts all the S10/ 83 to 91 Camaro / 78 to 87 A and G body brake hardware.

Thanks for the info.

What's a B-body? Deep down I'm a MoPar guy and that means roadrunner, Charger, Super Bee to me.

Will those 12" brakes fit inside a 15" diameter American Racing 5 spoke?

He does want a center console but the one he currently has is for an automatic. He was thinking he was going to have to shell out some long green for a 4-spd console but, if it would have to be modified anyway for a 5-spd maybe we can work with the one he has.

Is that aftermarket spindle taller, shorter or the same as the stock one?

[wayne petty]

i used to have a 66 gto also.,...  i still have dreams about driving that car...

before you go any father... spend the 5 bucks on ebay and get the frame dimension chart...    hopefully the cross members has not collapsed like most do...   what happens is do to the force of the car hitting dips, the suspension levers the frame rails inward .... this affects the ability to get the wheels aligned...   you cannot take out enough shims to get the camber anywhere near correct...

my gto was so bent that i could not get the headers in..  there was no room... once i got them in... after flattening them  i could not get the starter in..    once i found out the problem... i pulled the motor and porta powered it back open... i have forgotten the dimension between the upper control arm mounting brackets... as that is the dimension that you need...

it is possible for others... to use a pair of heavy duty type frame pulling chains, a 20 ton bottle jack, a scrap of steel plate, and a 5 or 6  foot length of 3 or 4 inch W beam (wide top and bottom) or other steel jacking beam to pull the frame open without pulling the motor... takes about an hour...

i am not trying to scare anybody away from these classics.. only an invisible problem that affects many older cars... that is easily fixed...

you can also tell if the cross member is bent... the motor mount bolts won't come out or go in easily... the holes just won't line up... when it is straight ... they slide right in...

takes just a few minutes to measure the distance between the upper control arm mounting points...  even with the motor in...   park the car on a level place..    put a stick across the fenders over the points to be measured and masking tape it in place...  use a plumb bob hanging over the stick...  mark the stick where the string hangs.. do the other side and measure between the marks...

all you need then is the proper measurement from the frame chart or one of the rodders who knows it...

oh.. and the other tips are correct....   i did the 68 to 72 brakes on my 66... along with the 408 rat, scattershield, wide ratio muncie, 4:11 12 bolt posi , L60-15 caldwell recaps. it was a lot of fun.... i did run 205-60-14's on the front...  it handled better i thought.. but i was young then...

[zzebby]

Go with the 71 or 72 Chevelle spindles and brakes.  I've done quite a few and simple and all factory stuff.  Reasonably low cost too,  a local guy fixes me up for about $250,  all used stuff.   If he's not a road racer and is watching the $  then you can't beat it.
Also true on the frame rails coming together.  Very common with these.  I just take it to the frame shop while it is apart. Cheap bend job.

[enjenjo]

Thanks for the info.

What's a B-body? Deep down I'm a MoPar guy and that means roadrunner, Charger, Super Bee to me.

A GM B body is the full size cars from that make, Chevy Caprice, Pontiac Bonneville, Olds 88, Caddy deville. A C body is the big cars, Buick 225, Olds 98 Caddy, Fleetwood. Of course that all changed in the 80s.

Will those 12" brakes fit inside a 15" diameter American Racing 5 spoke?

Depends. current production, yes, old 60s wheels, no.

He does want a center console but the one he currently has is for an automatic. He was thinking he was going to have to shell out some long green for a 4-spd console but, if it would have to be modified anyway for a 5-spd maybe we can work with the one he has.

An auto console might work better for a 5 speed, the shifter on both are pretty much centered.

Is that aftermarket spindle taller, shorter or the same as the stock one?

Same as the stock one.

[sirstude]

The 4 speed console will work with a Richmond 5 speed.  Stay away from the Richmond 6 speed, the top gears are really weak.

Doug