I am still gathering info on a mild engine upgrade I am doing. I have a 1976 l48. Auto. 3.08 gears. TH350 Trans. I am planning on putting Eldelbrock E-street 64cc heads and a Xe262 camshaft. My question is the operating rpm range of the cam is 1500 to 5500 rpm. From my research I think I will be fine with the factory torque converter. Am I missing something or am I headed in the right direction. Thanks.

 

The stock TQ should be fine, but adding some stall would help coming off the line with the 3.08 gears.

 

Would you think 2300 to 2700 would be the right neighborhood if I went that way?

 

With that small a cam I would leave the stock converter in. The problem with low stall aftermarket converters is they are cheap and made poorly. The stock one was made here and should last a long while behind your engine.

 

Thanks for your input. Much appreciated.

 

What's the rush for a converter? Why not do the engine mods first and then see what your 60 foot times are.

 

Thats something to consider.

 

I have changed the stall on my L48 twice. First to 2400 then to 3000. Both were a huge help to the engine with a th350 and a 3.08 rear diff.
now have a 3.55 dif with a 3000 stall. Having a higher stall makes the car so much more fun and torquey when you stomp it.
don't buy the cheap junk ones from summit or similar. Stick with good brand that offer adjustment to the stall if it's not to your liking.

I wouldn't drive mine without a higher stall converter at this point.

 

The stock converter makes my 79 L48 Auto a dog, even with 3.55 gears.

The correct solution is to add a third pedal (which I'm doing), but if you are keeping the auto, follow @REELAV8R's advice.

 

For more fun after a higher stall put a shift kit in the th350. Mine shifts hard enough at wot to break the tires loose I. 1st to 2nd shift.
and yet it shifts normal when not on the throttle. It's a nice addition IMO.

 

I've not had my '76 Corvette TH350 Auto for very long I've only taken it out a few times and it's in storage for the winter now. Anyway the few times that I did take it out I had the following problem, in drive if you set off slowly (slight gas) the car would to stall, however if you gave it a bit (not much) throttle it would want to go off like a bullet, spinning the back wheels. Great on a drag strip but not great if the roads were busy, wet or narrow.

I don't know too much about the engine in the car but I know it's been upgraded and have been told it may be 350 or 400hp. As fun as this is it makes the car a little wild when low speed precise driving in required ie parking, especially in reverse, reversing on a slight incline is almost impossible as it either will stall or if you give it all little gas it will be hard to control.

One way I managed to calm it down a little would be when at a stop to put the parking brake on and the when wanting to set off press the gas until the car pulled forward and then at the exact time take the parking brake off. This helped stop the stall as I could now give it a little more gas whilst having some control over the car.

Here in the UK automatic gearboxes were not very common until quite recently, everything was manual, automatics have become popular over the last 10 years or so but obviously modern automatic gearboxes are vastly different to the TH350, so now hold the car on a steep hill, won't stall, etc.

I guess i'm not used to the car and the idiosyncrasies of the gear box, but any tips to get the best out of the car, engine and gearbox would be appreciated.

 

I would consider how you intend to drive the car, if you think you’re going to be leaving hard often, you’ll enjoy the car more with a higher stall.
or if you intend to go drag racing. Wayyy better 60 foots

 

I'll put my shift kit, high stall TH350 up against a manual trans any day. It'll shift a lot faster than most can shift a manual.

 

It'll shift faster than anyone can shift a manual! Absolutely anyone.
it also sucks ALL the fun out of driving a sports car.
I just don't care that your auto can shift faster than a human.
4 on the floor for me!

 

LOL! I'm not dissing the manual transmission. I love manual transmissions. I'm just saying for people who are always putting down the auto. You just don't have it set up right. Done right it's an absolute blast. And it capable of equal or better performance than the manual. If you've never experienced this then you've never ridden in a well sorted auto transmission.
I'll agree, in stock form it's a pig. But so was the motor and the performance of the vehicle as a whole.
So if an auto is what you've got...then work with what you got. I had no interest in swapping to a manual In my case. The Auto in there takes a licking and keeps on ticking. I manual shift it and hammer it regularly, never a bit of trouble or complaint from it.

 

And this is why I suggested that anyone using an auto follow your advice on high stall torque converters.

 

On my LS swaps the LS builds were fairly mild. I used 2800-3000 stall Yank or Circle billet converters. They drove like a stocker until you put the foot down. Make sure to add a big trans cooler if you don't have one already.

 

Like mentioned, that is a rather small cam, MUCH smaller than my current cam and I'm running a 9.5" 3200 Yank with a 3.31 gear. I comes out of the bottom pretty nicely and runs 12.5. I plan on going to a 3500 since when you brake stall it, I'm just a tad low and the 3500 should put me where I want to be at launch. A re-stall at Yank is only $300, not bad. BTW, the Yank drives like stock on the street until you stick your foot into it. I would run it first and see where you are at with the 60' and go from there or do all the math and try and get it right from the start. Choice is yours.

 

10.5:1 cr 383 sbc with XR276HR-10 cam (1900-5600 rpm). Th400 with 336 gear. Put in a 2600 stall converter and didn't like it. With Magnaflows, too many revs and noise from a stoplight, without going anywhere. Couldn't get used to it. Had to change the rear main seal and swapped in a 2200 and like it much better.

As mentioned previously, if you are going to race it often, go higher stall. For cruising and an occasional stoplight to stoplight romp, I would likely not stay stock, but consider a 2200 stall as it works great for me.

BTW.. the 2600 was custom built and was 11", and the 2200 was B&M (Summit) and looked tiny in comparison at 9". Couldn't find info on the differences in sizes - pros and cons. Also, have heard the adage several times about buying a good one vs. cheap one, but not much in the why. What does a driver experience with cheap vs expensive? Can anyone help with that?

 

It would appear that if you had a 2600 on the street and took too much to get it going at a light, it was a rather loose converter and that will produce a lot of heat. Like I said, I'm running a 3200 on the street and runs exactly like stock with a light throttle at a light until you hit the loud peddle and then hang on. Who's TC was the 2600? I had a 2400 TCI 11" at one time and I trough it in the trash, what a POS!