[Chief of the 60's]

Originally Posted by 242177P

Twice a year, 40 miles, round trip.

Stop telling him what you would do. SBC, 700R4, 9 inch.

We're not talking toques and back bacon here. Please chime in when you can speak "transmission".

[Carmine]

Originally Posted by Chief of the 60's

That right there is a text book example of an oxymoron.

Here is some food for thought as well as looking at this from an economical angle. That car with any non-OD tranny will tach at around 3800 RPM at 55 mph. With an OD, that same car, same engine and same rear gear will tach at about 2200-2400 RPM at 55 mph.

Now, without even talking about fuel economy, an engine that is running at a much lower RPM will last a hell of a lot longer because it is experiencing a lot less wear & tear.

There are also no tunnel mods necessary for a 700R4/4L60/4L60e.

Thanks for the info on the overdrive transmissions. What I said in my last post, I would never consider it an oxymoron. Occasional action at a red light and a trip down the 1340 once a year, if that ever happens, is far from abuse or beating this car. No slicks. No headers. No 4.33 gears. No motor changes. Just a little more get up and go with a transmission change would be fine with me. These cars when purchased new back in the day, I'm sure were subjected to abuse. Seen alot of them at the drags. Different story now, at least for me, Carmine.

[Chief of the 60's]

Originally Posted by Carmine

Thanks for the info on the overdrive transmissions. What I said in my last post, I would never consider it an oxymoron. Occasional action at a red light and a trip down the 1340 once a year, if that ever happens, is far from abuse or beating this car. No slicks. No headers. No 4.33 gears. No motor changes. Just a little more get up and go with a transmission change would be fine with me. These cars when purchased new back in the day, I'm sure were subjected to abuse. Seen alot of them at the drags. Different story now, at least for me, Carmine.

If you only knew. Ha Ha! There was a parking lot between 2 buildings where Pontiacs were being built. That parking lot was known as the dragstrip.

[The Champ]

Originally Posted by Chief of the 60's

Here is some food for thought as well as looking at this from an economical angle. That car with any non-OD tranny will tach at around 3800 RPM at 55 mph. With an OD, that same car, same engine and same rear gear will tach at about 2200-2400 RPM at 55 mph.

Sorry, late to this party...

In what alternative universe to you live in Chief?

With tires close to the OE tire height (27" - maybe a common 255/60/15 ), with a non overdrive transmission will tach a little over 2400 RPM at 55 MPH.

Even with 26" tall tires (say a 235/60/15), that car would only hit a little over 2500 RPM.

Or if it was being run with 14" wheels with the widest available 245/60/14's (25.6" tall), it would only be reading 2566 RPM at 55 MPH.

To hit 3800 RPM, the tires would have to be around 17" tall or the car.

Can I point out that the car would be traveling over 80 MPH with the 245/60/14's or 86 MPH with the 27" tires.

The amount of incorrect information you post here is legendary. I won't even go into the other wildly inaccurate info you have posted in this thread...

Carry on, I need the laughs...

[Sirrotica]

FWIW, in 1967 GM did the swap for GTO owners and put the 440 ft.lb. rated T400 in these cars. A bone stock one can be broken with a healthy running 400 with street tires, from my own torture testing back in the day. Since you can break a stock T400 with street tires and a warmed over 400, I myself wouldn't recommend a T350 which is even less torque capacity than a stock T400, but the OP can decide for himself.

A short tail T 400 only needs a shortened driveshaft, and move the crossmember back (very easy to do, done at least a dozen of these swaps over the years). Everything else hooks to the T300 lines, shift linkage with minor tweaks to the shift cable bracket which have to be done with a T400 or a T350.

[242177P]

Originally Posted by Sirrotica

FWIW, in 1967 ...

The folks that designed the Powerglide back in 1950 would simply not believe the point to which it has evolved. I love the TH400, but even I have to admit the TH350 is quite capable.

[Sirrotica]

Originally Posted by 242177P

The folks that designed the Powerglide back in 1950 would simply not believe the point to which it has evolved. I love the TH400, but even I have to admit the TH350 is quite capable.

From a core standpoint, the 2 transmissions are going to be near the same price point. GMs engineering department already made the determination over 5 decades ago which transmission was superior in a muscle car.

Any muscle car near 400 CU IN came from the factory with the T400, not the 350, (until the smog era choked engines, where GM reconsidered using a 350 in Trans Ams). The reason was warranty claims, and the 400 would survive long enough to get a muscle car past warranty. In interest of longevity, the monetary investment is going to be close to equal, why wouldn't the OP go for at least what GM deemed adequate at the time the car was new? Shortening the driveshaft a couple inches, and moving the crossmember back a like amount, would surely be worth the added torque capacity to avoid breaking parts.

I fail to understand why when talking muscle cars, and the abuse they sustain, (because that's why people own them in the first place), the attitude is to use inferior engineered parts today, because it might be a little less work, or someone might save a couple hundred or so dollars over the stronger engineered parts.

It might seem like a great idea initially, but when you're laying on your back the second time under the car, removing a broken transmission that you thought would be adequate, the false economy of the original decision somehow fades quickly. I've been there and done it, and comments I post here on PY are a lifetime learned as a mechanic, and muscle car owner of nothing but Pontiac muscle cars, and racing them, and thrashing them for decades. First muscle car owned was a 67 326 HO Firebird bought in 1969 from the dealership I worked at, and I have owned and worked on literally dozens of my own, and other customers Pontiac rides to gain my knowledge and pass on recommendations.

Street use, oval track, autocross, road course, and yes more than a few straight line acceleration contests. Been there, built them, broke them and fixed them until the breakage was at a bare minimum. Conducting the torture testing so others could profit from my testing...……………

My testing program was done from my own wallet and making my living twisting wrenches on my own, and other peoples mostly Pontiac musclecars. The third picture in my signature shows the backdrop of Pontiacs in the late 70s and early 80s of my service station and garage where we specialized in Pontiacs. Now if someone has done more breaking of parts, and cost them more money, and time than my own testing program has, I'll gladly yield to their opinions, fair enough? I'll return to the earlier comment I made, "You can't build too strong, but you can definitely build too weak."

[66sprint6]

We did the TH350 swap as it was just so darn easy., which is what we needed. We don't have a lot of resources to do much else. It certainly does everything we need it to. We were considering the 200-R4, but they are pretty hard to come by used. They haven't been made in a long time. We rarely venture far from home with the car, but if we ever do, it would be nice to have the overdrive. So it's on our wish list for now.

[Sirrotica]

FWIW, the 4L80E was made from 1991-2013, tons of cores out there in GMC, chevy light duty trucks and medium duty motorhomes etc. Up to 18,000 lbs chassis. A stock 4L80e is nearly as strong as a built 200 is, more work initially, but reliability is worth something.

[dbiggs]

Question about the TH350...I did the swap to TH350 but am having trouble finding the right tube...anyone have any idea what will fit a '66? Ordered one aftermarket and tried a couple others and none fit.

[66sprint6]

If you are talking about the dipstick tube, then I can tell you that aftermarket sucks. Every one that we tried didn't fit and they leaked like a bugger. We finally found a used GM dipstick tube on eBay and problem solved.

[b-man]

Originally Posted by dbiggs

Question about the TH350...I did the swap to TH350 but am having trouble finding the right tube...anyone have any idea what will fit a '66? Ordered one aftermarket and tried a couple others and none fit.

Look for a factory dipstick and tube from an A-body (‘72 and earlier) that originally came equipped with a TH350. I found one here on the forums by posting a ‘parts wanted’ ad, from a 1970 Tempest or Le Mans to fit my ‘64 Le Mans with a TH350 swap.

I used a similar strategy when I put a TH400 in another ‘64, using a ‘69 GP TH400 dipstick and tube which is the same a an A-body in this regard.

[meangene]

Originally Posted by Sirrotica

FWIW, the 4L80E was made from 1991-2013, tons of cores out there in GMC, chevy light duty trucks and medium duty motorhomes etc. Up to 18,000 lbs chassis. A stock 4L80e is nearly as strong as a built 200 is, more work initially, but reliability is worth something.

Art Carr would laugh at that statement/ https://www.cpttransmission.com/ is as nearly as strong as a built 200

[Sirrotica]

Originally Posted by meangene

Art Carr would laugh at that statement/ https://www.cpttransmission.com/

Really, maybe he'd better check out the torque ratings of a stock 4L80E!!

Anythime Art Carr wants to send me one of his 200s and I'll install it in my diesel dually and see if it makes 270,000 miles without failure. No doubt in my mind that even with $4000 dollars worth of billet parts and labor my diesel will have no trouble breaking it pulling a trailer and truck combo at 14,000 lbs. shifting through the gears at WOT.....

Seems in his advertising he also sells 4L80Es, there wouldn't be any need for him to build 4L80Es if a 200 will suffice, would there?

[meangene]

we replace them 4L80E in are company plow trucks all the time and i sure are Art would sell you one /and we where talking a better fit, no computer to run the 200r4

[Sirrotica]

Originally Posted by meangene

we replace them 4L80E in are company plow truck all the time and i sure are Art would sell you one

I don't need one, at 270,000 miles its just fine, BTW it's a K3500 and I use it to plow, tow, everything and anything, still going strong. Maybe you need someone that knows how to plow snow, replace the operator instead of replacing transmissions.

Why aren't you replacing the 4L80E with a 200, they must be stronger according to you and Art, right? Why is Art selling 4L80Es?

You'll never convince me that a 200 is stronger than a 4L80E, but hey knock yourself out. Doubtful that any person with a grip on reality would side with you, but maybe you can convince someone of it.

Next you'll be telling me a Dynaflo is stronger than a 4L80E......……………….LMAO Now it's my turn to laugh...…………….

[Chief of the 60's]

Originally Posted by meangene

we replace them 4L80E in are company plow trucks all the time and i sure are Art would sell you one /and we where talking a better fit, no computer to run the 200r4

Funniest thing I have read all day.

[Chief of the 60's]

Originally Posted by Sirrotica

Really, maybe he'd better check out the torque ratings of a stock 4L80E!!

Anythime Art Carr wants to send me one of his 200s and I'll install it in my diesel dually and see if it makes 270,000 miles without failure. No doubt in my mind that even with $4000 dollars worth of billet parts and labor my diesel will have no trouble breaking it pulling a trailer and truck combo at 14,000 lbs. shifting through the gears at WOT.....

Seems in his advertising he also sells 4L80Es, there wouldn't be any need for him to build 4L80Es if a 200 will suffice, would there?

He doesn't know what he is talking about. I have trannys built by Art Carr, he knows his chit and certainly would agree with you.

[connman]

I owned a 66 GTO since 1968. It rusted so bad that it was unsafe to drive about 20 years ago. During that time I had 12/13 motors in the car, from 326/389/455. And 350/400 SBC and 454 BBC. Transmissions ranged from 350/400 and the 4 speed muncie and a TKO600 5 speed OD. [ In my present 66 Lemans with a Ford 3:50 9". The 350 is an easy swap. It will bolt right in. Course a different flywheel is needed. The drive shaft will bolt right in. Watch out for a BOP case as chevrolet bolt pattern is different if you are buying one used. Also watch out for the ones with a lock up converter as they are not built to take the horsepower as the early ones. Also watch out because someone may try to sell you a 200 transmission as they look close to the same. The 200 has no modulator if I remember right. Rear trans mount bolts right in. The 2 speed rear mount is the same if I remember right. If you only go 40 miles out of town then the 350 is the way to go. If not I would put a 200R4 in it. I have never done that swap, but from what I read, [ I use to get every performance GM andHot Rod magazine. I still get 8/10 ] it is also a bolt in. Remember, they used it in the Grand National Turbo's. Example 3:55 rear gear 70 MPH 350/400 3200 RPM 4 speed 2900 RPM 5 speed OD TKO 600 2400 RPM and 1200 RPM at 40 MPH. I haveto hit 42 MPH before I put it in OD. Since you are stayig stock on the motor, You do not need a high horsepower transmission . I hope this info helps you.

[Carmine]

Good info. Thank you, Carmine.