[Spridgets] First drive on new engine

[Robert E. Shlafer]

As suggested by mfgr. in original owner's
handbook. 

"Ridges" don't form for many miles. But before you've got 3-5k, do some WOT 
accelerations to redline in 2nd/3rd gear. 

Otherwise, you can minimize the metal loss to internal parts during breakin by "rubbing" them against one another with "normal" loading ("burnishing") or you can maximize metal loss ("tearing off") during break-in by un-necessarily FORCING them against one another by "loading" heavily (WOT accelerations or "lugging").

Of course, if you can easily R&R motors yourself and/or do your own engine rebuilding, or pay others to do it and don't
mind most likely spending more money than you have to sooner than you need to, drive the hell out of it during "break-in". :):)

Mfg. recommends to vary rpm's constantly
during the first 500 miles. In the owner's
handbook.

Not in the owner's handbook: Keep the runs on the short side during the first
500 miles allowing the motor to "cycle"
(warm/cool between runs).

Drain the oil and change the filter after the
first 100 miles when oil contamination with metal particles will normally be greatest. No sense un-necessarily circulating RELATIVELY heavily contaminated (metal particles) oil through the internals for no
good reason ("cheap insurance" so to speak).

CapBob 

P.S. - The less metal you "take off" of interal parts during break-in, the longer serviceable clearances between parts will exist, all other factors being/remaining equal.