Engine/auto trans break in

My first rodeo with an auto trans. Is there a break in period for the trans? 727 all new internals. I see 5 qts capacity and 3.5 for 11" converter, how do you account for cooler and lines? add as needed during engine break in? I dont want to interrupt the engine break in if i dont have to.

You would already want a qt or two in the converter when it was bolted together & trans in neutral & add more when you fire it. good idea to have several helpers, one to man the dist/timing light, one to check for (mainly fuel) leaks, one to add fluid, you in the drivers seat to keep the RPM up/gun the eng/watch the gauges/shout orders. fill the trans to full to start.

The initial fill will depend on the pan used; with a dry trans and a stock pan, pour 6 quarts into the trans (any more can be tossed out the breather) and a quart in the converter.

Make the initial startup in Neutral with the rear wheels free to turn, leave a funnel in the dipstick tube and immediately pour in another 2 quarts after startup. After engine break in, run the trans through all the gears, set the parking brake, then check the level with the dipstick idling in Neutral and adjust as necessary.

I would toss a disposable trans filter in the cooler line like a magnafine with a magnet. If your not crazy about leaving it in, then remove it after a few hundred miles

Yeah, what John said. I just broke in my new 440 and rebuilt tranny. Tranny builder said make sure it's in neutral for break in and have several extra quarts and a funnel at the ready.