Will This Converter Bolt Up to My Flywheel?

Switch Pitch only applies to the THM400, you should have a THM350 so the first doesn't apply to you

Lock up converters are on the 2004R, and 700R4, and later transmissions. Again, doesn't apply.

Most flexplates are drilled for both bolt patterns. You can confirm that by unbolting the inspection cover and looking.

You have a small block.

You get what you pay for with torque converters. The best way is to buy a converter made for your application. Buying one off the shelf is hit or miss. Why do you need a converter? Why is the stock one not satisfactory? Have you replaced the cam?

 

There is no way to know where it will stall in YOUR CAR. There is no such thing as a converter that will stall at 2800 RPM or any other RPM in every car. That is why there is a range specified in the description of the Jegs converter, but even that could be inaccurate. What cam do you have?

 

TA says stock converter OK with that cam. I'd be very careful about buying a converter. It is no fun driving a car with a converter that is too loose. It gets old real fast. Like I said, you get what you pay for. I wouldn't want more than 2300 stall with that cam, and I'd want it to feel like a stock converter when street driving. That doesn't come cheap, it just doesn't unless you are very lucky.

 

Yeah, that will happen sometimes. Lots of guys don't come across the right way, and some lack a lot of tact when trying to get their message across. If you were standing right opposite them and talking in person, it's likely you would get a lot more out of the conversation, and you wouldn't feel ridiculed.

Whenever you change something big like a cam, you end up having to make other changes to get the most out of it. It can be a very frustrating experience when you get a lot of differing opinions about what you should do. The worse thing you can do is start talking about it on another thread, because there is no reference point for guys to start commenting. Stay on the thread you were getting nowhere on. Eventually it will lead somewhere. I think Cliff R had some comments about a TA212 equipped engine. I'll try to find them. That might help. It's really important to know if the cam was degreed properly. It is also very important to have AT LEAST 12* initial timing, with all the mechanical advance in by 2500 RPM.

---------- Post added at 04:49 PM ---------- Previous post was at 04:33 PM ----------

OK, this post by Cliff Ruggles is good to read,

"The factory q-jet is application specific. Your engine combo is FAR from the factory set-up.

Once you get the idle system up to par, it will idle perfectly in and out of gear.

Edelbrock and Holley carburetors are "non-emission", so they have very generous idle fuel delivery set-ups.

The idle system used on the q-jet is superior to either one of those designs, as most used a built-in idle air-bypass system. This is basically a controlled vacuum leak, to keep the throttle angle low, and off the main system at idle speeds.

The Edelbrock Performer series carburetors are OK, easy to tune, and plenty of parts support. They are not very efficient, lacking sensitivity to the primary boosters, so you really have to be on your "game" to get them dialed in for fuel economy, without sacrificing throttle response and driveability. This statement holds true for all "high performance" carburetors with large primary bore area and small boosters. Doesn't mean they woln't work, but there is always comprimise to those designs. Huge airflow capabilities reduce "signal" to the boosters at low engine speeds, so they are never as efficient as spread bore designs.

We don't use or recomend the Edelbrock Performer series carburetors here, simply because there is no adjustment whatsoever for the opening rate of the secondary airflap. If it works good on your set-up, you are a lottery winner.

Most stumble/hesitate/bog when going quickly to full throttle. At least on cars with excellent power to weight ratios. The ones I've tested here are usually OK, if you have a small engine pushing around a really heavy car, and not a lot of gear or converter.

My engine absolutely HATES them, and it is impossible to go quickly to full throttle in any gear, vehicles speed or engine rpm without some SERIOUS stumbling. The slower the engine rpms' and vehicle speed, the worse they "lay down". I can bolt the same carb on a 305 SBC engine in a pick-up truck with big tires and 3.08 gears, and the owner will love it so much he'll take it off the engine at night and sleep with it!

In any case, the q-jet will work as good as or better than anything else, IF you take the time to set it up exactly for what you are doing. I would NOT install bushings on the secondary side of the throttle body, but I would make sure the huge throttle plates are well indexed and FULLY seated when closed, with some clearance in the linkage so they aren't tipped in slightly. Go after the idle tubes, idle down channel restrictions, and idle bypass air, when you use the right sizes, it will idle perfectly in and out of gear.

It also helps to make sure the distributor is working like it's supposed to, and not adding any additional timing from the mechanical advance at idle speed. I see this a LOT, and it is difficult, if not near impossible to tune a carburetor when this is occurring.....Cliff"

Also, read ALL of Cliff's comments in this thread, http://www.v8buick.com/showthread.php?230408-buick-jet-amp-rod-sizes&highlight=TA+212+camshaft

Especially post #25,
"I just finished working on a 1968 Buick GS with a 350 and that cam. Pretty interesting findings, if you don't mind a long read.

I built the correct numbers matching carb for it, and the owner supplied the basic information for the engine and drivetrain. Stock rebuild on the engine a few years ago, and they intalled the T/A Performance 212 camshaft. 2 speed trans and 3.23 gearing.

Since the owner was local, he asked me to install the carb for him. I upgraded the carb for modern fuel, and added an external APT screw so I could raise the metering rods to fine tune part throttle A/F.

I opened up the idle tubes to .036", and idle downchannel restrictions at .052". The carb wasn't set up for idle bypass air, and I didn't figure it would need it.

Prior to the install, the owner said the engine ran OK, but pinged a tad at WOT, with some "gurgling" as it pulled up thru low gear (2 Speed Auto). He biggest complaint was idle quality, basically, it idled like crap.

The distributor had been sent out and "custom tuned", so I just installed the carb and fired it up. It ran great on the fast idle, but pretty "rough" at curb idle, with a LOT of "lope". The mixture screws would kill off the engine, but when backed all the way out wouldn't give it enough idle fuel.

I also noticed that the distributor was set at 8 degrees initial timing, and add a TON of timing via the mechanical and vacuum advance curves. The vacuum unit was adjustable for spring tension, but not for amount of advance. It had what looked like a piece of aquarium hose on the bent part of the arm to reduce the travel some.

Anyhow, I worked with the carb for a while, then told the owner we needed to pull the distributor and recurve it.

He happened to have another one in the trunk as a spare, so I did that one instead. I reduced the mechanical advance to 11 degrees (22 at the crank).

This allowed me to raise the base timing to 12 degrees, providing 34 total. I MIG welded up the vacuum unit to add another 15 degrees timing via ported vacuum.

The distributor was installed, and base timing set at 12 degrees. This smoothed out the idle some, but it just wasn't enough. Even with the idle mixture screws just about falling out of the carb, I could place my hand over the choke housing and it would smooth out ever to slightly.

I pulled the carb and drilled the idle downchannel restrictions to .058". Once back in place, I had plenty of idle fuel, and ended up setting them at 3.5 turns out from seated.

Between adding idle fuel, and initial timing, the heavy "lope" was not gone, and the engine idled pretty smooth, with a "deep/heavy" sound. It liked to be idling about 800rpm's, then fell to about 600rpm's in gear, smooth and steady.

To sort of sum things up here, I was quite surprised at how "big" the little 112 cam acted in the relatively high compression 350 engine. Vacuum wasn't really all that low, but it did require some additional ignition timing and idle fuel delivery from the carb to be happy at idle speed. Stock settings just weren't going to cut it......Cliff"

 

Now you are talking. Good Luck.