FocusGhia

I'm about to order a new th700r4 transmission from Probuilt.
I will also be getting a new torque converter and I'm curious as to what stall speed I should go for?

My plans are for a different enginein future so my current engine will progress no further.
The idea is to get the correct converter for this engine and get a new one for the new engine in future.

The engine is a 305 TPI.
Rear gearing is 3.43:1 posi

The car has headers and high flow exhaust system (decat), ported plenum, 47psi fuel pressure, Performance Resource prom, tpis air filters and descreened maf.

On the street it runs the std 16" IROC rims but at the strip it runs 275 BFG drag radials.


The car is mainly a street driven car (in a lot of heavy traffic) and gets to the strip once or twice a month in the summer.

What stall speed would be appropriate and what is the downisde of having too high a stall speed when it comes to highway cruising?

FocusGhia

I forgot to mention I will also be fitting the usual chassis components for better strip performance (lca, sfc's, panhard bar etc).

NYIROC

For a mostly street car I wouldn't go higher than 2400-2500 stall.

Stock on these cars are 1600-1700 stall. You'll be slipping too much in 4th gear with higher stall speeds than 2500.

I would add an external tranny cooler too to help keep the transmisson temps down.

Regards,
G

Chris89GTA

iTrader: (2)

Slipping too much in 4th w/ more than a 2500?? What?? 700s are lock up converters, so by the time you get to 4th, the converter locks up and you have a 1:1 lock w/ the motor and transmission.

NYIROC

Good point. I forgot the lockup function.

nape

iTrader: (1)

Never had a 305 F-body, but I had a 2800 in my '91 GTA and that car loved the converter. Drove it rain, shine, snow or ice, wasn't even that unruly.

Whenever I buy one for my new car, I'll be going 3200-3400. This one isn't a daily driver though.

89gta383

iTrader: (5)

2800 stall

LilJayV10

iTrader: (5)

Ask dana when you order the tranny, he will be able to help you. I will say he is conservative on stall speed though, he will say that too though.

Pro-built :hail:

Mark 89Formula

2600-2800 RPM works well with a 9.5"-10" converter like the Vigilante or Yank and a mild engine. Recommend a slightly tighter converter if you go to a larger diameter, say 2200-2400 RPM. Good idea to run an external tranny cooler in series with your stock cooler no matter what converter you choose.