I've recenlty swapped a 5.7 into my 86 IROC and I now need a tranny for it. I was wondering if i should get a strong 700r4, or could i convert to a 4L60E. I was wondering if they make converison kits from 700r4 to 4l60E? Thanks.

 

Yep, they do. There's a computer you need to get to control the 4L60E. It cost about $700 last time I checked.

I'm not sure why it would make sense though. For all that money you get the exact same trans but the ability to control exactly when it shifts. I debated doing that, but put the money into a better 700R4 and a high stall.

 

How much torque do you plan on eventually putting through your drivetrain. I did NOT pay enough attention to the different 'stages' of the trans buildups and my naivity got taken avantage of by a trans shop that had a great reputation. If you think you're going to go over 400 lb torque, you might want to look into steping up to the 4L80E. That should be the last automatic overdrive you'll ever need. Plus, one of the major performance manufactures, just designed a new gearing that gives a better launch and adds 35% more overdrive (makes for better fuel economy or usefulness of 3.7ish rear end gears) Nitro

 

I plan to put out about 350+ torque.
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I plan to put out about 350+ torque. but no more than 400.