I'm currently in the process of swapping an LSA and 4L80e into my 1972 Chevelle and I'm curious on what to do with a converter. I swapped out the Cam, 2.4 upper pulley and C&R heat exchanger so I'm guessing I'll have around 625RWHP. Rearend is a 12 bolt w/ 3.73 gears and the trans is a 4L80e rebuilt with Jakes Stage 2 kit w/ billet input shaft and hardened front hub. My question is this.....do i NEED an aftermarket converter? I'm gonna blow the tires off no matter what with this thing so I don't really wanna make it worse. Car is not a race car nor ever will be. Its a weekend only/summer cruiser/car show car. If there is no performance advantage w/out traction, I'd rather put $900 elsewhere, however, if a stock converter is gonna possibly shred my transo, maybe its a good investment. Advice? Thanks!

 

Stock converter will be fine for this application.

 

625 rwhp is a lot of power for a stock converter. I think I'd talk that one over with one of the torque converter vendors on the forum to see what they think about it. If the converter goes it will likely take out the trans with it.

 

Stock converter will struggle with your power. I just pulled a 4l80 PTC single disk 3500 from my car ill part with. Went to a triple disk and lower stall for the street. Like the poster before me, speak to a vendor and run it by them.

 

The converter comes with this engine stock yeah?

 

Stock auto trans is a 6L90e. I have a 4L80e behind it.

 

The stock LSA 6L90 is a very nice converter, 300mm twin disk with flanged hub and brazed internals. They also have a unique stator over the regular 6L80 and work great with the LSA torque curve. I have never tried the bigger 310mm 4L80 OE converter on that combo, not sure it could handle the power, RPM or work well with the torque curve. You are also going to run into a problem assuming you are running the OE crank, it is an 8 bolt crank with the LS bolt converter circle and will not fit the bigger 4L80 bolt pattern. Be happy to discuss options if you want to give us a call.

Chris