Original Thread: http://www.camaros.net/forums/showthread.php?t=97021

Switching from a Powerglide to a TH350. Decision has been made, I will not being going with a 200R4 or 700R4, so please keep that in mind. I simply do not drive enough to justify the additional cost. Not one local builder would touch a 200, and the changes for the 700 were more than I wanted.

With that being said, here are my specs:

Holley 600CFM #80457-2
GM Intake # GM CFM 14057053
Heads: #333882 1.94INT 1.5EXH 76CC - future change
Cam: unknown, probably stock - future change
HEI Distributor
Hooker headers
Flowmaster 2 1/2" exhaust with X-over pipe
10 Bolt rear - 2.73:1
Tire size: 25.4"

65MPH = 2400 RPM

Transmission builder will be adding shift kit, he says 2500 stall converter. I'm thinking that's too high, but am looking for ideas. I don't completely understand the stall ratings on converters. Most of the recommendations I had on the old post was 2000 stall.

I use the car primarily for rides, no racing. Street 50%, highway 50%. +/-

Thanks!
Bryan

1800-2000 RPM stall.
GM had a factory P6 converter IIRC,you can get those cheap.Stalls 2000-2200 approx . Your local trans shop should be able to locate one for you. Last time I bought one rebuilt it was $70,,, but that was like 15 years ago.

Transmission builder will be adding shift kit, he says 2500 stall converter. I'm thinking that's too high, but am looking for ideas. I don't completely understand the stall ratings on converters. Most of the recommendations I had on the old post was 2000 stall.

I use the car primarily for rides, no racing. Street 50%, highway 50%. +/-

The 2.7 gears with drop round town and high way below mine...a 350 with 308 posi gears on 14x 60x 235 rubber sry dont know wheel diam off hand

I had a 2500 stall in it upto a week ago....at highway 60/70 mph on slight hill or slight throttle there was a little slipage
Around town 30/40 mph rpms are about 1200 /1600 rpm ok on the flat but a small hill /rise, traffic, even "granny footing" rpm slippage goes from 1200 to 2200.
So I posted a similar question a few days ago...
Have decided for a 1200/1400 rebuilt stock converter

Like u my car is a daily, about 50/50 city open road.. was going to a 700, but finance circumstances have prevented that (Wife decided to go to University full time for next 4 yrs)
But I have also gone for everything to work at low rpms 1200 to 4500 rpm
Low duration cam, even advanced 2 deg
Bottom end response carb 450 cfm
Stock rams horns instread of headers designed to to at high rpm
Gm HEI dizzy
2 1/2" dual exhaust with X-over pipe..
performer dual plane.

I hope to get the trans/converter in tomorrow and test..
I except far better round town milage, slightly better open road cruising
As expected from comments made to my post.
As to the accidently blipping the tyres all the time, maybe will fix that???
Dropping the throttle at an intersection and lightly up...not using brake, maybe not?? or not as dramatic
On a wet road, pulling out into traffic having to wait for a big gap cause wheels just spin, maybe make that gap smaller also.

No more than a 2000 with 2.73 gears.

Chad,

That's what you had mentioned before. What would happen with the 2500?

Bryan

The trans. would build alot of heat in around town driving due to converter slippage.Excessive heat shortens trans. life.

If going to higher stall rpm, you might think about adding an external oil cooler in series with the radiator oil cooler. As said, higher stall, more heat generated.

The trans. would build alot of heat in around town driving due to converter slippage.Excessive heat shortens trans. life.
No in prctice even then will not build enough to shorten life...but if doing a lot of heavy towing, then it will.
A lot is made of big coolers for a street car...this is not so, in practice the raditor cooler is enough or a well placed small cooler..
I have mind mounted at the bottom of the radiator strur leaning back level with the front chassis strut
And I have done quite a bit of towing , transporting my vintage cars behind the Camaro with the 2500 stall for 22 yrs
Stripped the trans last week..everything shows NO sign of any wear.

I guess my question is why would the trans builder spec a 2500? He has 25 years of experience building racing transmissions, is he thinking racing? What would I feel as a difference. Just trying to get a handle on what difference I would see between a 2000/2500? As I said before, I do not fully understand converters. If I travel at 2400 rpm highway, and have a 2500 stall, it's slipping right? Would I be better off with of stall that matches or is lower my highway rpm's? (Like the 2000)

Goal: Better acceleration, that PG is a boring old dog.

Just tryin' to learn...
Bryan

I guess my question is why would the trans builder spec a 2500? He has 25 years of experience building racing transmissions, is he thinking racing?
Ah ha so u have the same thing in the States as here
Engine builders, yrs of experiance, suggest cams heads etc way over what the intended user needs or to run efectively
Why have I a 2500? because a expert of 30 odd yrs building trans race engines etc said that would suit me...
Why am I going to a 1200/1400? becuse ?I went to a trans builder (with US experance also...who is not into hot cars, just rebuilding daily shopping baskets.. then spending the weekends fishing...AND because the advice of practical bottom line guys here like JimM..
Another example. my 20 yr old son is doing a mint RX7..started out with plans fully turbo, and double over head dipsticks etc...then hes hooked up with some rotary guys in their 40s...now going to a carbed engine, bit of mild porting...yeah they have there drag cars, but they also have very quick street cars for show...carbed..Save $10,000 on engine cost, goes a long way to a nice engine bay.

I guess my question is why would the trans builder spec a 2500? He has 25 years of experience building racing transmissions, is he thinking racing? What would I feel as a difference. Just trying to get a handle on what difference I would see between a 2000/2500? As I said before, I do not fully understand converters. If I travel at 2400 rpm highway, and have a 2500 stall, it's slipping right? Would I be better off with of stall that matches or is lower my highway rpm's? Goal: Better acceleration, that PG is a boring old dog.
Just tryin' to learn...BryanNo problem in learning. The camshaft, gears, engine torque, tires used, and weight of the car are some factors in choosing a convertor.

First, at cruise rpm, the conv is not slipping, very minimal at most. Slight throttle is given to accell, not alot.

You'll feel alittle Seat-Of-the-Pants difference between 2000 & 2500, again, dependent upon engine torque. Take a conv, one engine and it will stall at 1800. Put another larger/longer stroke engine in front of the conv, and it will stall higher.

I had a 3100 lb car w/350/PG/stock conv, ran 14.2X's. I installed a 10-inch/2500 conv, ran 13.4X's.

The lower first gear in the TH350 will give you much better acceleration and feel than the PG even with a stock converter.Unless you plan on a really big cam and rear gear changes in the future I dont think you need more than a 2000 with your current combo.When you do swap cams go with this http://store.summitracing.com/partdetail.asp?part=EDL%2D2102&autoview=sku
Like Everett said its about the whole combo.JMO