break in oil

what kind of oil should i use to break in my motor.
its a 5.0 bored out to a 309. i have bought
forged silvolite hyperutectic pistons, and
forged power seal rings.

another ?, i had the heads reworked and new valve seals
and valves put in. port polished too. should i upgrade
my cam. its a factory spec cam. anyone have any
suggestions?

30W, Don't use a high detergent oil, you don't need it to break in, with a quart of GM Engine Oil Suppliment. Yes get a cam, just because you will like it. Make sure to follow the breakin prociedjures for a camshaft as well.

thanks buddy, what kind of cam would you
recomend. the car is a 86 trans am and
its going to be a daily driver for my brother.
it came with a 305 h.o. the oil pressure
was pretty low so we have decided to drop
this other motor in it. will the roller cam from
the h.o. engine work in the 309?

if the motor was a factory roller motor you can use the roller cam. if the motor was a flat tappet motor you will have to get a rerofit cam,cam button etc...
use regular 10w30 motor oil to break in your motor.
make sure you do not use synthetic.
btw break in oil is one of the dumbest terms i have ever heard because the term break in oil was used in the sense that the oil in your motor from the factory is the oil that is in during the break in procedure. there is no such thing as break in oil.

i know that there is no such thing as break in oil,
everything in the motor is new and i just
wanted to know what kind of oil is the best
to break it in. that way the rings would seat
properly. but thanks for your response.

i use castrol 10w30 but thats the same as any other oil.

Esso Ultra 10-30 oil.. I know it'l probably be the only time you'l hear that.. But its proven itself time and time again.. Excellant break-in oil.. Actually its an excellant oil to use all around

another break-in note when on the highway dont drive at same speeds, don't rev the motor over 3250 rpm and also don't
lug it to much. The best thing is small changes in speed, 80,100,105,110,75,80, etc. (km's)

If its the L69 High Output 305, it came with a good cam but I guess if you wanted you could look into an aftermarket camshaft.