Motor will be ready shortly and looking for the right convertor. As the heading says 429 cubes with a custom 250 cam LSA 110. Rear end 3.73 with 4l60e tran.

Car is driven daily will be doing some circuit work and some 1\4 passes. More time spent on the first two, concerned about traction as we cannot get more than 265 rubber under rear end at present was wondering if would be better sticking with a lower str.

The setup is not for drags but would like to be able to get some numbers, looking for good allround convertor any suggestions.

 

Still looking for some help on this any body have an opinion.

 

Need some details about how much power and your goals.
The SS3800 would be good all-around choices for an NA motor. The PS 4200 or YTP 4000 would be better choices for racing. For a stealthy, very drivable, street car the SS 3600 would be fine given all the torque that motor should make.

 

Waiting to see what the LSX manifold will do if not great we will go with a custom intake, chasing the the best the motor will give without going to the ragged edge.

IMO these big motors should easily put out 600 horses and 550ft tq with good setup.

My driving goal is not all out drag car but more off an allround performer i will only go drags to put some numbers on the board but the car will mainly be driven on the street and circuit.

 

I would tend to be very conservative on converter selection for a big inch, high torque application like this one. This engine will make a converter stall much higher than its advertised rating. A 3000 stall would probably go around 3800. A 3500 converter would probably go 4300-4400. I would go with something advertised around 3000, such as the TCI 242931. It would work great in an everyday driver.
Kevin

 

Ditto^^ Check out the TCI SSF 3500, great streetable converter, like Kevin said all that torque your making will ascend the stall of the converter...Good Luck

Wes

 

Thanks for the replies.

 

The Yank's tend to stall about 10% higher than rated behind the big cube motors. However very few, if any have put up 550 ft-lbs with the current manifold.
Also, the new manifolds seemed to be focused on higher rpm power which means your peak 550 ft-lbs may occur at 4800 rpm. To get the most from it you'll want to stall to around 4400.

 

The guys are right that you will see a higher stall behind our 422+ motors. You're looking at about 3,800 for the SY3500 which falls int he 10% margin described by Ragtop 99. There's another 200 when you toss a 100-150 shot out of the hole on the SY3500 which probably isn't there with their E products.

Don't go below 3,500 or you're going to miss out on some fun. The tighter SS lines will be very streetable for you. It only takes 2-3 days for your foot to grow into your new converter.

The road ciruit work is where I'm at a loss though. The 265's will not be enough meat to keep you on the road behind this motor and anything that hits harder than the SY3500 is my guess because the 2.2+ STRs are going to break loose at the most in opportune times on such a small tire. So what you road course guys think??

Rick