All my engines get broken in on the Dyno. With a solid lifter cam the first 15 mins @1800 rpm allow for cam breakin. Quick check of the lash, then WOT pulls start. For roller motors just a warm up, check lash, then WOT.
The rings need load to breakin properly, It usually takes 4-5 pulls to get the rings in.
Properly built engines are best broken in fast. No need to play around breaking it in nice.

 

so what if you do a new tranny at the same time? should you beat the **** out of the tranny too?

 

well flt has told several members the proper way to break in their trans is to do a burnout out of their driveway

 

thats one way to do it lol. never had a rebuilt trans so wasn't sure.

 

if the tranny goes in drive and rev. and shifts good in the first 400 ft. then then stop and mash that bitch!!!

 

lol.... people just like to beat on there **** here... i figure if your going ot baby it your whole life that go easy on the break in.....but if you want ot have fun with it then beat the **** out of it....

and for the tranny...just make sure it shifts fine at first like stated above and then give her hell!

 

As for my humble .02 --->

I was taught to break in the engine in steps. First, the cam (unless roller). Usually the cam manuf. will specify. Next, seat the rings. Put the trans in a manual range and hammer down! Run the rpms up and let off, using the trans to slow the vehicle. In theory, this achieves max. engine vacuum and allows the cylinders/rings to cool. Repeat this like 10 times. The bearings should be fine if you haven't already spun one.

As far as the trans goes, I like to drive it a little just to make sure that there aren't any obvious problems before I kill it (I don't have a dyno, duh). If you buy a trans from a specialist like FLT, they have already dyno'd it and given it their seal of approval long before they turn you loose with it, so give that ***** hell!

I know, seems like a bunch of but that's what I've always practiced and it seems to work for me.